Cambridge businesses evacuated due to high CO levels, crews work to contain 3rd manhole explosion

CAMBRIDGE, Mass. — Harvard Square in Cambridge was closed to vehicle and pedestrian traffic amid a large emergency response following manhole explosions and “high levels” of carbon monoxide on Wednesday morning, officials said.

Firefighters responded to a report of a fire in the area of 27 Brattle Street around 9 a.m. and found a smoking and flaming manhole, according to the Cambridge Fire Department.

Cambridge police officers diverted traffic around the area in an effort to ensure the public’s safety.

“If at all possible, people should continue to avoid traveling through Harvard Square until further notice,” Cambridge police said in a tweet around 10:30 a.m.

Buildings in the area that have been exposed to carbon monoxide were evacuated and aired out as firefighters monitored the situation.

Just before 12:30 p.m., police announced that the scene had been “consolidated” and that JFK Street was back open to traffic.

Eversource officials were called to the scene to assist with the emergency response.

Just before 4 p.m., Fire Chief Cahill provided an update regarding the ongoing operations in Harvard Square following the two manhole fires, saying Eversource crews are working to contain an active third manhole that is producing excessive carbon monoxide to the surrounding buildings.

“It’s a dangerous, dangerous gas,” said Chief Cahill.

The containment is expected to extend into the evening and there is no timeline at this point on when the businesses will be reopening.

“It’s always challenging when you get into these basements, and you identify the high levels of this dangerous gas,” said Cahill.

This is an active and ongoing scene.

One firefighter was transported with non-life-threatening injuries due to possible smoke inhalation.

This is a developing story. Check back for updates as more information becomes available.

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