SAN FRANCISCO (CBS SF) — An evacuation request in the area of a gas leak and explosion on Mission Street in San Francisco was lifted Monday afternoon once the incident was resolved, according to authorities.

The San Francisco Fire Department’s public information officer tweeted that the gas leak had been contained at about 3:30 p.m.

UPDATE 3900 Mission Street Gas leak: INCIDENT RESOLVED ALL OCCUPANTS CAN RETURN No injuries Evacuation request lifted City Services and @RedCrossBayArea standing by to assist those affected if applicable @mayoredlee 1532 Hrs pic.twitter.com/FNdWoNb9dq — San Francisco Fire (@sffdpio) November 27, 2017

San Francisco fire fighters were called to the 3900 block of Mission Street near St. Mary’s Avenue shortly before 10 a.m. to investigate a gas odor in the area, according to fire officials.

When they arrived on scene, there was a heavy smell of gas in the area, Battalion Chief Rex Hale said.

PG&E crews were also called to the scene.

At 10:14 a.m., an explosion occurred in the lower floors of 3987 Mission St., a three-story residential building, causing moderate damage to

the home and blowing out its front windows.

No one was inside the building and no injuries were reported.

The San Francisco Fire Fighters Local 798 Twitter account posted about the incident shortly after 11 a.m.

3971 MISSION ST, GAS LEAK TURNED INTO AN EXPLOSION IFO ADDRESS, EVACUATING NEARBY BUILDINGS #SFFD and @PGE4Me on scene. @sfmta_muni pic.twitter.com/nkZEhZ1Etg — SF Firefighters 798 (@SFFFLocal798) November 27, 2017

Firefighters evacuated 19 addresses on Mission Street, College Terrace and Bosworth Street.

ALERTSF: Cont. to avoid the area of Mission St & St. Marys Ave due to SFFD activity. YMCA at 4080 Mission St. available as an evacuation center. pic.twitter.com/OPud24s0fw — San Francisco Fire (@sffdpio) November 27, 2017

KPIX 5 reporter Susie Steimle said that approximately 100 people were evacuated from the neighborhood.

19 apartments, roughly 100 people evacuated on Mission street due to gas explosion. Fire officials believe it started in the garage and blew out the windows of an apartment building. PG&E still working to turn off gas line. pic.twitter.com/TTodxOulbH — Susie Steimle (@SusieSteimle) November 27, 2017

The explosion apparently happened after the initial reports of a gas leak. The incident appears to have happened at a residence on Mission Street near St. Mary’s Avenue.

“They positioned an apparatus away from the building and started walking up when it exploded,” said Hale.

While the official cause is being investigated, Hale said they have a general idea of what happened.

“I would expect gas was filling up the garage. It hit a pilot light and that caused the explosion,” explained Hale.

Neighbors worry this is a recurring problem, as there was a gas leak on the same block a couple of weeks ago.

“It was someone on the street who called 911. And it’s hitting pretty close to home because it’s happening across the street now,” said neighbor Keerthana Hanumanthagowda.

PG&E refused to respond to our requests for comment for more than six hours. Moments before airtime a spokesperson provided a brief statement on why it took so long to stop the gas leak.

“We turned off the gas as quickly and safely as possible,” said PG&E spokesperson Andrea Menniti.

Window blinds and debris from what was reportedly a garage door appeared to have been blown off of the two buildings affected by the incident.

Mission Street is closed near the location as PG&E crews were digging into the street at several locations trying to stop the gas flow from the leak.

PG&E workers were able to stop the flow of gas as of shortly after 1 p.m. The gas smell was reportedly noticeable within a four-block radius around the incident.

It did not appear that there was a PG&E project in the area. A PG&E spokesperson said that it was unclear what had caused the incident.

One Muni bus was stopped turning off of Mission Street and the street closure is impacting several bus lines, including the 14 and 49 lines.

Hale said the leak appears to have been outside on the street in front of the building and it is unclear how the gas got inside.

Officials said that most of the 100 people evacuated during the incident should be able to return home by 7 p.m. However, Mission Street will remain closed into the evening as PG&E continues it’s investigation.

Some 400 people were still without gas due to the utility shutting down lines for the incident.

The YMCA at 4080 Mission Street was opened as an evacuation center for those in need Monday afternoon.

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