(Reuters) - A parade float carrying wounded veterans that was hit by a freight train had entered a rail crossing when warning bells and lights were going off, seconds before the crash that killed four men, a federal investigator said Saturday.
The four veterans were on a flatbed truck that was hit on Thursday in Midland, Texas. Another 16 people were injured.
The warning signals at the crossing went off 20 seconds before the collision, as a first truck carrying veterans was safely crossing the tracks, said National Transportation Safety Board member Mark Rosekind.
Investigators on Monday will conduct a "sight distance test" to understand what the train engineer and the driver of the truck that was struck might have seen before the collision, Rosekind said.
"You know there was a lot of activity going on with other noises going on," Rosekind said.
Robert Accetta, lead NTSB investigator on the crash, said his team had not yet interviewed the driver. "We don't know what the driver may or may not have seen," he said.
NTSB officials declined to identify the driver or the company that owned the truck.
The crash in Midland occurred during a "Show of Support" parade that was to kick off a weekend of events to salute U.S. veterans of the wars in Iraq and Afghanistan.
Some veterans and their spouses aboard the float jumped off to escape the collision in the seconds before it happened.
Pam Shoemaker, who was riding in the float that crossed the tracks ahead of the one that was struck, said earlier this week she saw a railroad crossing bar come down just before the crash.