NEWTON (CBS) – An MBTA Green Line operator has been placed on leave after a train derailed in Newton Wednesday morning.

The two-car D line branch train derailed at a track switch just outside of Riverside station shortly after 6 a.m. One passenger was on the train at the time and no one was hurt.

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A Grren Line D branch train derailed outside of Riverside Station, Aug. 7, 2019. (WBZ-TV)

MBTA spokesman Joe Pesaturo said investigators are focusing on the operator, who was hired back in March.

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“The preliminary investigation shows the train’s operator did not have the signal system’s authorization to proceed. By not allowing the track switch to be properly aligned, the second car of the train came off the rails,” Pesaturo said in a statement, adding that there were no issues with the “track infrastructure, the signals, nor the train.”

The operator’s name has not been made public.

A Grren Line D branch train derailed outside of Riverside Station, Aug. 7, 2019. (WBZ-TV)

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The car was put back on the rails at 11 a.m. and regular service on the D branch resumed just before noon.