Published: Nov 17, 2012 9:23 PM EST

MIDLAND, Texas (AP) - Federal investigators say the warning signals at a railroad crossing in West Texas were activated before a parade float crossed the tracks in an accident that killed military veterans.
    
National Transportation Safety Board member Mark Rosekind made that announcement at a news conference Saturday. He said the signals had been activated seven seconds before the float crossed the tracks.
    
Four veterans of Iraq and Afghanistan were killed Thursday when a freight train slammed into the parade float in Midland. Sixteen people were injured.
    
Rosekind said the NTSB reconstructed the accident using video cameras from the train and a sheriff's vehicle.
    
He said the train started sounding its horn nine seconds before it hit the float. The train engineer also used the emergency brake five seconds before the crash.