Driver of trailer in veterans' train crash is under doctor's care SAN ANGELO, Texas (Reuters) - The driver of a truck involved in a deadly collision with a train during a Texas veterans' parade last week has been put under the care of a doctor and is not yet able to be interviewed by investigators, the driver's lawyer said on Tuesday. Four veterans wounded in Iraq or Afghanistan died on November 15 when a Union Pacific freight train plowed into the flatbed trailer they were sitting on, and 16 others were injured. For the first time on Tuesday, the driver of the truck pulling the trailer was identified publicly as Dale Andrew Hayden, 50, of Midland, Texas, a veteran and active military reservist, his attorney, Doug Fletcher, said. Hayden is "under physician care," Fletcher said, and the National Transportation Safety Board will wait for medical clearance before interviewing him. It was not clear what illness Hayden was suffering. Hayden's testimony is key to the investigation because authorities believe the sound and lights warning that a train was approaching worked properly. Eyewitnesses said the barricade arm came down on the trailer as it was crossing the railroad tracks. The NTSB was re-enacting the accident on Tuesday to try to help determine the cause. Union Pacific has blamed the driver of the truck for the accident. Fletcher said he was representing Hayden and Smith Industries, the driver's employer. The veterans killed in the crash were identified as Marine Chief Warrant Officer Gary Stouffer, 37; Army Sergeant Major Lawrence Boivin, 47; Army Sergeant Major William Lubbers, 43; and Army Sergeant Joshua Michael, 34. Also on Tuesday, the city of Midland, a booming oil city in West Texas, said the parade sponsored by the private "Show of Support" group, did not have a permit. Editing by Greg McCune and Peter Cooney