NORTH CAROLINA - Investigators said warning signals at a railroad crossing were activated before a float carrying wounded veterans crossed the tracks.
The crash on Thursday killed four veterans, three of them from North Carolina. Overall, 16 others were injured in the accident.
The National Transportation Safety Board has been in Texas since the accident trying to determine what exactly happened.
Investigators found the train sounded a horn nine seconds before the crash and signals were going off seven seconds before the float went over the tracks.
The NTSB will stay on the scene for at least another week
, then take their evidence back to Washington, D.C. for analysis.