MIDLAND, Tex. -- Federal officials investigating the collision of a train and a truck that killed four people at a parade here said Saturday that the vehicle carrying veterans and their spouses tried to cross the tracks seconds after the railroad crossing's bells-and-lights warning system was activated.
Mark R. Rosekind, a member of the National Transportation Safety Board, told reporters on Saturday that investigators had examined video and mechanical train data from the accident.
That evidence showed that 20 seconds before the collision, the crossing's warning system came on, as they were required to under federal railroad regulations. Eight seconds later, Mr. Rosekind said, the truck's front crossed the first of the track's two rails as the arm guards began slowly coming down and the crossing lights flashed and bells were sounded.
Investigators with the transportation board have not identified the truck's driver, and they said they had not yet interviewed him. Because officials are still conducting their on-scene investigation, they stopped short of blaming the truck driver for the crash.
"We're not going to analyze it, we're just going to stay with the facts," Mr. Rosekind said. "There are a matter of seconds that the truck is actually in that area when the warning lights are going off."
The crash killed four Army and Marine veterans who were all wounded in action while serving in Iraq or Afghanistan. Sixteen other veterans and civilians were injured, though only five people remain hospitalized. Only one of the injured, a veteran's spouse, is in critical condition.
One of the injured veterans, Shane Ladner, released a statement on Saturday expressing support for the volunteer group that sponsored the parade and a hunting trip that has now been canceled, Show of Support Military Hunt.
"Prayers have been and continue to be answered," said Mr. Ladner, an Army veteran who is now a police officer in Holly Springs, Ga.
As residents prepared to gather for a prayer vigil at a downtown plaza on Saturday evening, federal investigators described the final 21 seconds before the collision, providing some answers but raising more questions about the truck driver's attempt to cross the tracks after the warning lights came on as well as about the train crew's actions. Mr. Rosekind said the train's emergency braking was not applied until five seconds before the collision.
The collision occurred at 4:36 p.m. Thursday, as the parade crossed over train tracks at South Garfield Street and West Industrial Avenue. The parade featured two trucks that carried wounded veterans and their spouses on seats attached to open flatbed trailers. The first truck crossed over the tracks, but the second -- carrying 12 veterans, 12 spouses and two escorts -- was struck by a Union Pacific freight train bound for Louisiana.
Witnesses said the gate arms had been up as the vehicles and motorcycles at the front of the parade passed the rail crossing. And they said the arms came down on the people seated on the trailer as the truck made its way across the tracks. Federal investigators on Saturday confirmed some of what witnesses reported, saying that seven seconds before impact, the gate arms struck the flag poles lining the flatbed trailer. They also said that examinations and inspections of the tracks and the locomotive engine found no defects or anomalies.
Officials said that as the truck tried to cross the tracks, the gates had started coming down but were not yet horizontal. There is a delay of a few seconds between when the warning lights and bells come on and when the gates are completely down. But investigators said federal regulations require traffic to stop once the warning system comes on.
"Once the crossing becomes active, when the bells and the lights start to flash on the mast, traffic is required to stop," said Robert Accetta, the transportation board's investigator in charge in Midland. "The gates come down in a delayed fashion there so that any traffic that may be crossing the tracks can clear the tracks, but they would be required initially to stop once the crossing becomes active."
Other questions remain about when the train sounded the horn. A Union Pacific spokesman, Tom Lange, said the train crew had properly sounded the horn, but witnesses said they heard the horn only a few seconds before impact, and parade participants near the front of the procession said they did not even realize a train was coming. Mr. Rosekind said that nine seconds before the collision, the train engineer sounded the horn.
Officials with the Federal Railroad Administration said that in most cases, the horn on a train must sound 15 to 20 seconds before the train arrives at the crossing. However, in designated quiet zones, the train engineer does not have to blast the horn but can make that call if it appears to be necessary. The crossing in Midland was one of those quiet zones, and traffic signs on nearby streets read "No train horn."
The train was traveling 62 miles per hour at the time of the accident. Union Pacific changed the speed limit for trains in Midland to 70 m.p.h. from 40 m.p.h. in 2006. A company spokeswoman said that the changes were approved by federal railroad officials, and that the company had not had any accidents at that crossing since the speed limit increased.
A 16-member team from the transportation board has been testing the signal system, inspecting the truck and checking to see if parade permit procedures were followed by the city, event organizers and Union Pacific. The authorities said the truck driver voluntarily supplied a blood sample to the police. Investigators plan to look at his qualifications, training and medical status.
This article originally appeared in The New York Times.