Transcript for At least 3 dead after Amtrak train derails

breaking news about that deadly train derailment in Washington state. Look at that scene yesterday. Height of rush hour. Trains dangling over one of the busiest interstates in the northwest and now we know that the train was traveling at 80 miles an hour in a 30-mile-per-hour zone. Yeah, it was the inaugural run on that particular track. You've seen the devastation from the exterior. We want to take you inside some of those cabins. These are the pictures from one of the survivors. It is incredible. Pictures incredible. Crazy to think some survived this after looking at some of those. So fortunate, so lucky. Here's what we know at this hour. At least three people were killed. More than 90 injured. 13 cars jumped the tracks on its first run. And it was the new route for the train and we'll go to ABC's Clayton Sandell on the scene in Dupont, Washington, who has more. Good morning, Clayton. Reporter: Good morning, Michael. You can see behind me here this is still a very active scene. We want to show you, you can see there is a big yellow crane that's beginning to remove train cars from the overpass at this hour. A major interstate below still shut down as investigators try and figure out what made this train go off the tracks. Oh, my god. Reporter: It was supposed to be a triumphant day but in an instant amtrak 501's inaugural run on a faster track turned into tragedy. A lot of melting and screeching and a lot of just being turned around. Reporter: This morning investigators are on the scene trying to determine what caused the passenger train to hurdle off an overpass. Sdmrt train was going at 80 -- about 80 miles per hour. Reporter: In a 30-mile-per-hour zone, right? That's right. Reporter: Railcars crashing into vehicles on the interstate below. Officials say so far three people from the train were killed. Over 100 injured. It was wet, it was cold. We had downed power lines. We also had downed trees. It was very slippery and there's no access to this scene except from I-5 so our responders%were climbing up and down this hill trying to get to those victims. Reporter: Amtrak cascades train 501 left just after 6:00 A.M. 85 passengers and crew on board. 7:34, a locomotive and 12 cars careening off both sides of the overpass. Amtrak 501, emergency, emergency, emergency, we are on the ground. Is there everybody okay? I'm still figuring that out. We got cars everywhere and down onto the highway. Reporter: The impact caused passengers to fly out of their seats. People were flying, you know, you're like, oh, my god. This is real and start to see the roof kind of peeling and it's just like is this ever going to stop? It was almost like being inside a dryer machine, shook completely to the other side of the taken and then back. Reporter: When Dan and his girlfriend came across the accident scene, the eagle scout sprang into action. There was injured people walking all over the place in shock and I was like, dude, somebody needs to just be a leader, sort of organize one of the trains had tipped upside down and kind of spilled the passengers out then the train came down on top of them. That's where I was like, whoa, this is gnarly and those victims were pretty badly beat up and when they were pinned under the train I grabbed the dude's hand and was like rubbing his back and I'm so impressed by you. You're a champion and just talking to him. Reporter: Now, one safety system that might have made a difference is called positive train control or PTC, you can think of it like an autopilot. If the train is going too fast, PTC automatically slows you down but officials say even though PTC was installed on these tracks, it had not yet been activated. George. Big problem there. Clayton, thanks very much.

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