Update: Trains are moving slowly through the tunnel as the SUV is off the rails, but still in the tunnel itself.
Shuttles are in place this morning between West Portal and Embarcadero Muni Metro stations after a car entered the tracks near San Francisco's Duboce Triangle neighborhood, according to a Muni spokesman.
A MUNI worker told NBC Bay Area that the SUV is "two to three blocks" into the tunnel.
As of 6 a.m. there was no Muni light-rail service on the L-Taraval, M-Ocean View, N-Judah, K-Ingleside, J-Church and T-Third Street lines.
Shuttles were put into place on surface streets, according to Muni spokesman Paul Rose.
An SUV went into the tunnel at Church and Duboce streets, Rose said. No injuries were reported and no trains were involved in the incident, Rose said.
A 40-year-old man named Scott Mitchell was arrested for suspicion of driving under the influence and failing to obey a traffic sign.
Emergency crews were trying to remove the car from the tracks and then repairs and testing will be needed, Rose said.
"This is going to take some time," he said. "I encourage commuters to consider other means of transit this morning."