Surveillance footage from the roof of an office building near the Amtrak crash site shows the harrowing calm in the moments before the derailment.
The footage from Tuesday night shows a dark night, with little to no action on screen until 9:23 p.m.
At 9:23.40, the train is seen going past in the upper right corner for four seconds with no clear indication of any problems.
Just two seconds later, however, a bright flash lights up the sky and a stream of smoke is visible.
Two similar flashes follow, with the time stamp reading 9:23.48.
The surveillance footage was taken from the roof of CSS International Corporation, an equipment manufacturing corporation.
Footage such as this as well as data recordings from inside the train will all be examined as evidence by the various investigative teams working to determine what caused the crash.
National Transportation Safety Board member Robert Sumwalt also noted at a news conference this evening that the train had a forward-facing video cameras so that footage will be incorporated into the investigation, as well.