CANTON — The National Transportation Safety Board has taken over the investigation into Thursday’s collision between two Union Pacific freight trains in McPherson County.

The two trains hit each other around 6 a.m. as one train was moving onto a side track to let the other pass. According to Eric Weiss with the NTSB, the investigation will include a check of the signals along the line, interviews with the train crews and a check of the locomotives event recorders, similar to a black box on a jet airliner. Weiss said that data and data from the signals along and before the siding have already been sent to the NTSB headquarters in Washington.

The area is regulated by Centralized Traffic Control, but there is no word on if a signal malfunction let the east bound train pass or if the crew missed the signal. Weiss said the NTSB will also look over information on the crew and their schedule to see if fatigue could have been a factor. The eastbound train hit the last 15 cars and the trailing locomotive of the westbound train as it was pulling onto the siding.

Weiss said the NTSB wants to know if a system known as Positive Train Control would have prevented the accident. PTC, as it is known, would have either alerted the locomotive engineer to a pending collision, or automatically stopped the train on its own. The somewhat controversial and expensive system is in the process of being installed across the United States.

UP has made repairs to the tracks and trains were running through the accident site by 1 a.m. Friday.