Four people are dead and 17 others are injured after a train slammed into a parade float heading to a US event honouring wounded veterans.
Union Pacific spokesman Tom Lange said the eastbound train was sounding its horn before it hit the float as it approached a railroad crossing in Midland, West Texas.
He said the crossing gate and lights were working at the time.
Mr Lange did not know if the train crew saw the float approaching.
City of Midland spokesman Ryan Stout says 10 of those injured are in critical condition at Midland Memorial Hospital, while the seven others are in stable condition.
The parade was set to end at a Hunt for Heroes banquet.