UPDATE: SF Appeal reports that Muni Spokesperson Judson True has confirmed the total amount of injuries is 47 -- 4 critical, 23 serious, and 20 minor. Light rail service is not expected to be restored for several hours.

UPDATE II: NBC Bay Area reports about an eye-witness account in which the L operator might have passed out prior to the collision. Another witness reported seeing the driver making gestures as if to say he could not stop the train. The operator was the most critically injured during the accident, and authorities have not been able to ascertain what happened.

At about 3 p.m., an L Taraval rear-ended a K Ingleside train at West Portal Station, shattering the windshield front window of the L train. CBS5 reports that about 60 passengers were injured, but fire officials told Streetsblog that there were 44 total injuries, all of which have left the scene. None of the injuries are described as life-threatening as of yet.

Light rail service on the K, L, and M lines is reportedly still halted in both directions. Buses are currently providing service between West Portal and Castro Station and West Portal and the western part of the city. A police officer told CNN that one of the train conductors miscalculated a turn, which is still being investigated.