BOSTON -- Two members of a track maintenance crew were killed Tuesday when a Massachusetts Bay Transportation Authority train struck a piece of track repair equipment in Woburn, Mass.

Officials said that the incident happened at about 1:30 p.m. at the Salem Street Bridge near the Anderson station in Woburn.

The victims have been identified as Christopher Macaulay, 30, of Brentwood, N.H., and James Zipps, 54, of Lowell. John Hickey, 50, and Edwin Olson, 55, both of Lowell, were injured in the crash, according to the Massachusetts Bay Commuter Railroad -- the company that employs the workers.

"MBCR is stunned and deeply saddened by today's horrific tragedy. Our hearts go out to the family and loved ones of these workers," MBCR General Counsel Richard A. Davey Jr. said.

One worker was on the equipment at the time of the crash, and five others were standing nearby, according to MBTA spokesman Joe Pesaturo. One worker was medflighted to a Boston hospital.

Ten passengers were taken to local hospitals after being "shaken up" in the crash, according to Pesaturo.

"They said, 'something was on the track. Everybody brace,' and it was just a big crash -- a big bang," passenger Jason Silva said. "I am alright. My knees hurt, but I am alright."

"We had no idea. I had no idea. I was reading at the time. I had no idea until it hit," passenger Alex Dembow said. "(The impact) was very quick. There was a very abrupt stop. A lot of people were thrown up in the air. The person a few seats in front of me had his knees go though one of the seats. There was a lot of confusion."

The train left Lowell, Mass., and was headed to Boston, according to MBTA spokeswoman Lydia Rivera. There were 43 passengers on board at the time of the crash.

MBTA officials said that at least eight trains earlier in the day passed the crew without incident. A dispatcher based in Somerville, Mass., may have made a mistake, officials said. The train should have been operated on a track that was parallel to the workers.

"They are doing track maintenance work," Pesaturo said. "I can't emphasize enough this is work that goes on every single day on the MBTA commuter rail system. This is critical track maintenance work that is absolutely necessary to keep the system running, safe and reliable. This was not a unique situation to have a work crew out on the right of way."

The MBTA bused rush-hour commuters on the Lowell Line.