MIDLAND, Texas (AP) — Organizers of a parade in West Texas in which four U.S. military veterans were killed when a train plowed into a truck had been using the same route for three years, investigators said Sunday.

National Transportation Safety Board spokesman Mark Rosekind also announced that oilfield services company Smith Industries was the owner of the truck that served as the float the veterans were on during Thursday's parade in Midland.

Rosekind said the company was cooperating with investigators, who expect to interview the driver on Monday. The NTSB declined to release the driver's name, and Rosekind said investigators don't know if the driver worked for Smith Industries.