Shortly before 7:30 a.m., Cambridge firefighters rushed to the Central Square Red Line stop to rescue a woman who'd fallen on the outbound tracks just as a train was pulling into the station.
The Cambridge Fire Department reports power was shut off and service halted in both directions as firefighters worked to extricate the person.
WBZ reports firefighters were able to get her out after about five minutes and get her to the hospital.
Power was restored around 7:50 a.m., but by then massive delays had built up along the Red Line as passengers waited at stations for promised shuttle buses that didn't always come.
The Central Square rescue came about 20 minutes after a track fire near JFK/UMass that caused lesser delays - although it is continuing to cause residual delays on the commuter-rail lines that also run through JFK/UMass.