(02-02) 20:32 PST SAN FRANCISCO --

Muni's K, L and M Metro lines are not running between the Church and West Portal stations because of downed wires inside the subway - and the shutdown is expected to last through the night. The J and N lines are unaffected.

Muni is running shuttle buses between Van Ness and West Portal, making stops at all intermediate stations but commuters may want to use alternate routes. Muni spokesman Paul Rose said crews would work all night to have repairs made by the morning commute. .

In the meantime: "If you're going anywhere from Van Ness to West Portal, you'll have to take one of the bus shuttles," he said.

The shutdown began shortly after 1:30 p.m., Rose said, when a train near Church Street station somehow pulled down the overhead wires that power the Metro lines. An investigation into the cause is under way.

"It's going to take some time to assess the damage, pull the train out and make repairs," Rose said.