SAN FRANCISCO (KCBS)  -- The city of San Francisco is considering a plan to close neighborhood fire houses on a rotating basis.

The City Controller's Office estimates the move could save $6 million a year, in the face of a $438 million budget deficit.

But some political leaders and firefighters say the rolling firehouse "brownout" could cost lives.

"It means lives, if our emergency personnel do not arrive on a scene in time," said State Assemblywoman Fiona Ma, D-12th District.

But Supervisor Chris Daly says the city may have no choice.

"Browning out firehouses may not be the most politically expedient thing to do... but it may not be the worst choice," said Daly.

The firefighters union Monday launched a campaign to douse rolling brownouts called "Save Our Neighborhood Firehouses."