HOXIE, Ark. (AP) — The National Transportation Safety Board says a trackside signal that could hold clues to a fatal head-on train collision in Arkansas was damaged in the crash but that investigators still hope to recover its data.

NTSB investigator Michael Hiller said Tuesday a southbound train was told to slow down as a northbound train approached a parallel track. He said it should have been directed to stop at the next signal, but that signal was mangled during the accident. Investigators hope they can recover its data and analyze the information.

The trains collided early Sunday, killing two Union Pacific employees and injuring two others near Hoxie in northeastern Arkansas.

The speed limit for trains near Hoxie is 50 mph. Emergency crews recovered each train’s data recorder.

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