A flagman who waved a pickup truck and a car into the path of an oncoming train at a crossing, killing one man and injuring three people, could face criminal charges, authorities said Friday.

The Union Pacific flagman, whose name was not released, apparently was unaware Thursday morning that the train was coming because of noise from nearby heavy machinery, said investigators from the Harris County sheriff's office."Now, it's in the hands of the district attorney," sheriff's deputy John Elzey said Friday night. "The DA will decide whether to file any charges in the case.

The pickup truck driver killed in the accident was identified as Henry Neal White, of Humble, Texas. His wife, Sara, and their 3-year-old grandson, Matthew White, were thrown from the truck.

The crossing's warning arms and flashing lights apparently were activated by the heavy equipment of a railroad crew working at the site, and the flagman was there to wave traffic through, Union Pacific spokesman John Bromley said.