BOSTON -- A Massachusetts Bay Transportation Authority train derailed Tuesday at a station in Cambridge.

The fourth car of a six-car train derailed shortly after 4 p.m. at the Alewife Station, according to Joe Pesaturo, of the MBTA. Sixty-five passengers were evacuated safely from the train, officials said.

"We left the station and the train jolted a little bit and kept going and jolted a little more. We were looking around trying to figure out what was going on," passenger Samantha Soloway said. "They told us that the train derailed and we would be going to the back of the train and walking back to Alewife."

The station is at the intersection of Alewife Brook Parkway and Cambridgepark West.

The derailment caused significant delays during the evening rush hour. Buses replaced Red Line service between Alewife and Harvard in both directions.

There were no reports of any injuries.

"There's always a lot of problems with the Red Line. I take it everyday," passenger Sephora Bernard said.

Pesaturo said investigators have begun looking into the cause of the crash. They are focusing on the rear wheels of the fourth car because the rail bed had no role in the derailment.

Commuters were advised to check with the MBTA for the line's status Wednesday.