the breaking news. the fib now called in on the train derailment. the conductor revealing new information about what she may have heard. was the train hit by some type of object? and the acceleration in the final seconds. the reaction coming in. the boston bomber sentenced to death. and the bomber's family. what they're now vowing to do. the reported tornado. 40 million bracing for a dangerous 24 hours. the abc news exclusive. bill cosby, breaking his silence right here, for the first time, right here. and the mystery fire at the vice president's house. the wealthy family gone. late details coming in. and, we remember an american legend. there was no one like him.

good evening, it's great to have you with us on a friday night. we begin with the breaking news from philadelphia. tonight, the fbi now on the case. and the new video showing the moments before the amtrak train derailed. speeding up as it reaches the curve. and new word about what the conductor may have heard. david kerley has 12kw4r50i6r7k9sds the story. >> reporter: tonight a look at the last seconds of amtrak 188 on the rails. racing past a closed circuit camera at more than 100 miles an hour. then just the flash of the derailment. was this train hit in the windshield by a projectile? a conductor on the train heard the engineer talking on the radio about possibly being hit like another train in the area. investigators talked to the 32-year-old engineer late today. >> he was specifically asked that question, and did not

recall anything of that sort, but there again, he does not have any recollection of anything past north philadelphia. >> reporter: but on the engine windshield there is an unusual round fracture. being called in to investigate that crack. >> at this point do we have any other information to corroborate a projectile or anything shooting at either of the trains, we are having the fbi to go out and examine the fracture pattern in the windshield. >> reporter: could that explain the sudden acceleration partially seen in these new pictures obtained by our station wpvi? ten minutes out of philadelphia it's at the speed limit. 70 miles an hour. then in the final minute a quick acceleration, 80 miles an hour then 90. just 16 seconds before derailment more than 100 miles an hour reaching that 50 mile an hour curve. the brakes are applied but it is too late. >> and david is with us live.

what will the fbi's first move be? >> they want help with forensics forensics. you can see a crack on the windshield. but the engine rolled over and i thought it was just from that action. they'll look at the mark on the windshield. was it a projectile? >> david, thank you. and in the meantime tonight, we turn to the breaking news out of boston. judgment day for dzhokhar tsarnaev, sentenced to death. tsarnaev, never looking at the jury showing no emotion as the verdict was read. and the images many believe sealed his fate. proof they say he felt no remorse. some lobbied for a life

sentence and his family vowing to try to save his life. tom llamas has the story. >> reporter: dzhokhar tsarnaev now knows where his path of terror will likely end -- in the execution chamber. >> he's now the youngest person on federal death row. all 12 jurors deciding he must tie for his crimes. liz norden has been in court almost every single day. >> i feel justice for my family. >> reporter: prosecutors argue he was unrepentant. the most damaging evidence this photo, showing him planting the bomb four feet from a row of children. including 8-year-old martin richard, who was killed. and this video, shot just 20 minutes after the blast.

tsarnaev shopping for milk. and this video, tsarnaev making an obscene gesture in his cell. proof, prosecutors say, he's not remorseful. the defense tried to paint him as a gentle boy and teenager that was drawn into jihad by his brother. and sister helen prejean met with him five typeimes and testified that he's genuinely sorry. but others are unconvinced. >> he wanted to go to hell and he's going to get there early. >> and tonight, abc news has reached tsarnaev's father south of russia. he tells us we will fight.

we will fight. we will fight until the end. david? >> tom, thank you. and dan abrams with me now. any question of an appeal? >> no question it will start fast and take a long time. it will take years if not decades. and the best he could hope for, a new trial. and that's unlikely. >> and the defense will likely focus on three jurors? >> that seem to have accepted the heart of the defense's argument. they still voted for death, but i expect the attorneys are going to focus on them in particular. >> and you point out, it could be years, if not decades ahead. and 40 million americans bracing for a blast of severe weather tonight into tomorrow. tornado watches, and reports of twisters already touching down. this funnel cloud, on highway 52

near denver. the hail making for a miserable drive home. and cars in fresno stranded. and in west hollywood, california drenching rains. a waterfall on the staircase. rob marciano from texas tonight. >> reporter: tonight, severe storms firing up. this funnel cloud in colorado. downed trees and a tornado reported near corpus christi, texas. people sheltering in this basement. near houston, over a half-foot of rain in the past 72 hours. the san jacinto river inching closer to this house. >> every time it floods like this it gets closer and closer. >> reporter: a nearby lake full officials releasing water from this dam. south of san antonio, high winds and heavy rain being blamed for this massive freight train derailment. miraculously no one injured.

record rain out west too. this los angeles stairwell turning into a waterfall. in fresno, tasha jones and her son escaping their nearly submerged vehicle. >> as a parent, the horrific part was seeing the fear on my child's face, trying to save us and get us out of the water. >> reporter: this western storm bringing over 7 inches of snow to the arizona mountains. it is that western storm that has the central u.s. prepping for a rough weekend. tonight, a tornado watch out for western nebraska and that zone ex expands to north texas. here in denton texas, the flood gates of this dam being opened in anticipation of more rain this weekend. now, to tragic news out of nepal. the six helicopters vanishing

after trying to help out after the earthquake. and wreckage foupdnd it's unlikely anyone survived. terry moran has the story. >> based on what we saw and the condition of the aircraft we believe there were no survivors. >> reporter: it was one of these helicopters. two bodies recovered today, none yet identified. families so far have only been told their loved ones were on board. this was the pilot, his family speaking tonight. >> i love you, chris. i'm proud of you. >> reporter: among those last this sergeant. and the day before the crash, this video shows others reportedly missing.

>> uh-1 yankee pilot here. we're able to deliver some rice potatoes and tarps to smaller villages. >> reporter: they all answered the call of duty. terry moran abc news. >> thank you. and now to iraq. ra ramadi overtaken by isis. families fleeing amid reports of suicide attacks and mass executions. and back at home in illinois, new video sparking allegations of excessive force. the officer appears to douse them with pepper spray. and that officer under investigation tonight. and in miami beach hundreds of cases being re-examined. steve osunsami with some of those e-mails tonight.

>> reporter: tonight, 16 miami beach police officers are having to explain themselves after being caught up in a racist and sexist e-mail scandal. >> and quite a few videos. that are congratulatic -- graphic pornography. >> reporter: their bosses say they sent around this photo a toddler holding the sign "dad" at a black history month parade, with a group of black men running away. and "black monopoly," where every space leads to jail. there was the "n"-word, the "f"-word, and plenty of porn. prosecutors say they now need to re-examine 540 cases where the officers were involved. women and african-americans are defendants in more than a third of the cases. >> this conduct seems to have to been accepted within the department. >> reporter: investigators say the writers with the most enthusiasm were lt. alex carula, fired thursday, and major angel vazquez, who retired last year. tonight, police in san francisco are also investigating 14 of their officers after discovering racist and homophobic text messages. in ft. lauderdale, they just

fired three officers and one retired for similar things. >> it jeopardizes criminal cases because these officers cannot be credible witnesses or arresting officers. >> reporter: in most of these cases, the messages were sent on city phones and email accounts. david? and now to an abc news exclusive tonight, bill cosby breaking his silence. sitting down with linsey davis in alabama, where he was meeting with students. take a look. >> reporter: if a young person comes up to you and says, you know, my mom says you've done some bad things, how will you answer them if they are pressing you? are you guilty? did you do it? are the allegations true? >> i'm not sure they will come like that. i think that many of them may say, well, you are a hypocrite. you say one thing. you say the other. my point is, okay, listen to me carefully.

i'm telling you where the road is out. now, you want to go here or you want to be concerned about who is giving you the message? >> reporter: more than 30 women coming forward in recent months. some accusing cosby of drugging or sexually assaulting them. cosby has never been criminally charged. and through his representatives have denied the allegations. some of your biggest supporters have said they are concerned about your legacy. and what would you like your legacy to be? >> i really know about what i want to do tomorrow. i have a ton of ideas to put on television about people and their love for each other. >> reporter: cosby, optimistic for the future but still reluctant to address or discuss the allegations about his past. linsey davis, abc news, month

good morningry, alabama. and breaking news at this hour. late developments coming in in the mystery mansion fire not far from the vice president's house. what did they discover in that home? nks . the iconic toy store closing. we'll tell you why. and the family that had no idea the airbag in their car was counterfeit, until our test. we'll be right back. my constipation and belly pain have my stomach feeling all knotted up. i've tried laxatives... but my symptoms keep returning. my constipation feels like a pile of bricks...

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cabinet. tonight, the family that had no idea their airbag was counterfeit. what to look for in your smartphone, the bike helmet, toothpaste and anti freeze. and this family stunned by their airbag. >> i'm bob, this is my wife tammy tammy. >> they bought the car, knowing they had to replace the airbag. what they didn't know it was from this guy. who tonight is behind bars. look at what investigators said they found in his home. more than 1,500 fake airbags, $60,000 hidden in the walls. he sold $1.5 million airbags on ebay. >> we found out later, the guy

that sold us an airbag sold us a bum bag. >> we offered to have their car towed and we're about to test their airbag. first, they set off a real airbag. and now, the airbag in the larsons' car. >> 2, 1. wow! >> a lot of shrapnel. you would have had a face full of plastic. >> a piece of the airbag cover over here. this is probably about 40 feet from the actual explosion of the airbag. can you imagine this being in the driver's face? >> and that's just one moment in the hour tonight. the investigation breaks just hours from now. we'll see what we found in makeup bike helmets, and canada drugs. the e-mail said it was cheaper,

but was any of it real? that's tonight on "20/20," at 10:00 p.m. when we come back a giant alligator, you'll see it here. and the mystery fire near the vice president's home. and do you remember this famous scene? word coming in that this toy store is closing. ♪ ♪ ♪ ♪ ♪ everybody's moving to garmin.

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authorityies finding no signs of forced entry. they're looking at a porch that was set on fire. and now, f.a.o. schwarz, an iconic toy story. word it's closing its flagship location in new york blaming the rent. and here just listen to ma'am mom. >> get back in the house. >> the gator heading up a neighbor's driveway. two kids at least they listened to mom. when we come back america singing the blues this friday as we remember a great, b.b. king. in a moment.

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finally tonight here remembering an american master, the king of blues, born in the mississippi delta, he had a profound influence on so many. there was only one b.b. king. the blues was in his name. nicknamed blues boy, which became b.b. ♪ >> that sound, uniquely his. his biggest hit, "the thrill the gone." ♪ the thrill is gone ♪ ♪ thrill is gone ♪ >> he said through the years, his fans would treat him like his last name king.

♪ everyday everyday i have the blues ♪ >> his partner through it all, his guitar lucille. he would say, his best friend. and eric clapton. >> i thank him from the bottom of my heart. >> that singular voice, defining the blues. ♪ yeah ♪ >> taking a final bow there, b.b. king remembered tonight. i'll see you for "20/20." until then, good night.

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