The truck entered the tracks after the warning lights went off. That means the veterans and their spouses had just a few seconds to jump off the float.
And at the same time.. the train's conductor pulled the emergency brake, trying desperately to stop in time.
The NTSB says the signals activated just seven seconds before the float crossed the tracks, and that the train started sounding its horn nine seconds before it hit the float.
The entire tragedy unfolded in just 20 seconds.
The truck that was hit was the second of two floats with wounded warriors, and the first one had already cleared the tracks.
Four veterans were killed and 16 others injured in the crash.