OKLAHOMA CITY (AP) - The National Transportation Safety Board says one of the two trains that collided head-on in western Oklahoma failed to take a side track and give the other locomotive the right of way.

NTSB spokesman Mark Rosekind said Monday night that one of the trains was supposed to move to a side track and wait for the other to pass. Rosekind declined to say whether it was the eastbound or westbound train that was on the wrong track.

Rosekind says no malfunction found in the signals that guide the trains.

Three of the four crew members assigned to the trains are still missing, though investigators fear they couldn't have survived the crash and tremendous fire.

One crew member jumped from the slower-moving train before the accident and survived.