After "the second car of an L Taraval derailed in the Twin Peaks tunnel between Castro and Forest Hill stations," reports SF Appeal, the entire Muni system is chaotic this morning. No injuries have been reported. The accident occurred at 7::35 a.m.

Shuttle buses will carry passengers between Castro and West Portal stations this morning. Buses, however, are reported to be "packed and miserable."

Expect major delays all morning. Per usual.