UPDATE, Monday 6:51 p.m. — The cause of the crash was human error.
Green Line service is suspended between Heath and Northeastern as officials clean up a train derailment from Monday afternoon.
One Green Line train failed to make a track switch and ran into another train about 4 p.m., according to Patch news partners WHDH.
Three people — two passengers and a trolley operator — were taken to the hospital for observation after complaining of back and neck pain.
Bus replacement service is ferrying passengers between the Northeastern and Heath Street stops of the E-line. The incident took place at Brigham Circle.