Around 11:30 a.m., a manhole exploded on Bush Street at Stockton Street, PG&E spokesman Joe Molica said.
Fire and police officials said smoke started coming from the area and the manhole cover flew off, striking a vehicle.
An employee at the Moth and Dagger Tattoo Studio at 610 Bush St. said the cover was blown about 4 feet into the air.
It struck a passing vehicle and dented the trunk, he said.
He said flames and smoke were seen coming from the exposed manhole.
The employee said down the block, it appeared another manhole cover had also come off.
Smoke from the area indicated possible damage to an electrical cable, Molica said.
No injuries were reported and as of 12:30 p.m., the area had been deemed safe, Molica said.
The employee at Moth and Dagger said police had blocked off two blocks of Bush Street as several fire trucks responded to the fire from the manhole.
The outage affecting residents and merchants in Chinatown and parts of North Beach was reported at 11:40 a.m.
PG&E crews are on scene this afternoon trying to restore power and are investigating the manhole incident, Molica said.
San Francisco Municipal Railway cable car service was briefly stopped after the explosion but was able to continue unaffected, Muni spokesman Paul Rose said.
