2 Green Line trolleys collide at Brigham Circle in Boston

BOSTON (WHDH) -- Human error caused two Green Line trolleys to collide on Huntington Avenue Monday, according to MBTA officials.

The two trains sideswiped each other when an inspector stationed at the crossover didn't manually switch the tracks which sent the inbound E train into the outbound train's tracks, causing the outbound train to derail, according to MBTA officials.

“The guy in the yellow who was supposed to be monitoring came out and was just yelling, ‘it was my fault, my fault,’” said Saousan Ramahan, a witness.

MBTA officials said just before 4 p.m. when the collision occurred.

MBTA officials said the outbound train had about two dozen people on board. Most damage was done to the inbound train.

“It was moving toward Boston and at the crossover, it started making the move over to the outbound track. It should not have. That’s why the switch was in the wrong position. If the switch had been in the right position, the train would have continued on to Boston. So it started moving over to the outbound track and that’s when another train -- moving in this direction -- came along and it made contact with the second car of that two-car train,” said Joe Pesaturo, MBTA spokesperson.

MBTA officials said two passengers were transported to a hospital with neck and back pains. The MBTA said a trolley operator was also hurt.

“I turned around and I think I saw someone also on the ground like they had fallen,” said Christopher Jelly, a passenger.

Passengers are being bused between Northeastern University and Heath Street. Restored train service isn't expected before Tuesday, according to MBTA officials.

The inspector who failed to make the track switch is said to be a 17 or 18-year veteran of the MBTA.