Two manhole explosions reported in downtown Boston near South Station

“I just heard chaos,” said Kilmain, 26, of Abington. He saw smoke, people running, and the injured woman on a stretcher.

Boston Police Sergeant Detective John Boyle, a department spokesman, said officers initially responded to the first manhole fire when the second one also caught fire.

“A female victim was transported to the hospital with injuries, and she’s being evaluated at Tufts Medical Center,” said Boston Deputy Fire Chief Brian Tully in a briefing at the scene. “When I pulled up on scene … the first thing I noticed was the glass on the sidewalk, and heavy smoke venting through the manhole cover.”

Tully said one manhole cover was “definitely pushed off onto the sidewalk. … It was several feet from the actual manhole, so it definitely … pressure lifted it up and it was tossed onto the sidewalk.”

The victim, Tully said, may have suffered a steam burn. Boyle said her injuries weren’t life-threatening.

“I think she may have been walking down the sidewalk when the manhole let go, but that’s speculation on my part at this point,” Tully said.

He added that utility crews were on scene to check for any natural gas issues resulting from the explosions, which prompted the evacuations of buildings at 175 Federal St. and 10 High St.

“We do have elevated levels of carbon monoxide [in thebuildings],” Tully said. “We’re in the process with positive pressure fans to bring the level down. … The levels are dropping dramatically.”

Tully said the elevated carbon monoxide levels were likely a “result” of the explosions.

“When we pulled up, there was a heavy smoke condition, especially out along that 10 High St.,” Tully said. “It’s been hot lately, so we’ve been using a lot of power around the city. So that probably, you know, it just kept on building up.”

Tully said officials hope the evacuated buildings will be able to reopen later Thursday.

“I think it’s just, you know, it’s Murphy’s Law,” Tully said. “When we use a ton of electricity and power, you know, the equipment’s just being overused, overtaxed, and eventually, you know, once in a while something breaks. But I believe the energy system in our city is safe.”

Ari Manakos, 30, of Dover, N.H, works at 155 Federal St. and said he could feel the building rumble while he was using a restroom.

”I was in the bathroom having a nice seat, and the room shook,” he said, while standing outside with some of his coworkers. “It was very, very audible. I felt the building rumble.”

He said he thought it was the elevator at first — until he heard the second explosion.

”It’s freaky,” he said. “No one wants to think about the concept of explosions happening.”

Another witness, Ashley Ventrillo, said she also heard both explosions.

“It was just terrifying because we didn’t know what was going on at the moment,” said Ventrillo, 25, of East Boston, who works for a law firm inside 175 Federal St.

She said she saw smoke coming from 10 High St. and detected a “horrible smell like gas.”

“It really sounded like a bomb,” she said. “When people started running, I started running because I was like, ‘I’m just gonna do what everybody else is doing.’”

Inside 175 Federal St., attorney Carmen Durso was preparing for a press conference at his desk on the fifth floor when, he said, he saw a strike of lightning between 10 High St. and 155 Federal St.

“I was startled because … it was clearly a lightning strike,” said Durso, a well-known attorney who represents sex abuse victims in civil proceedings. “And to see one between the buildings was just astounding. You would expect it to hit the buildings, but it very clearly came down there … it was immediate bang from the lightning and then the explosion.”

The lightning strike, Durso said, came seconds before the first explosion. He said he saw glass crash after the explosions and the power go out.

C.J. Certo, 29, was working at his computer at 155 Federal St. when he heard a “deep, really loud explosion,” he said at the scene.

“The building shook, kind of a quick jar and a human screamed,” Certo said.

He immediately fled the building.

”The boom and the scream were enough to get out of there,” Certo said. It smelled like ”chemical meets fear in the air,” he continued.

Some people’s natural instincts were to flee while others thought they were safer inside, Certo said.

”You could see the anxiety on people’s faces,” he said.

Eversource spokesman William Hinkle said the affected manholes belonged to the utility. He said no Eversource employees were working there at the time. The company now has crews on scene investigating the cause, he said, adding that no Eversource customers had lost electricity as a result of the blasts.

“We are working with the fire department and necessary utility companies … to conduct an investigation on the cause,” Hinkle said.

Video posted to Twitter by 7News showed smoke billowing from the manhole as Boston firefighters and police responded to the scene.

Jennifer Peter and John Ellement of the Globe staff contributed to this story. This is a breaking story that will be updated when more information is available.

Travis Andersen can be reached at travis.andersen@globe.com. Follow him on Twitter @TAGlobe. Matt Yan can be reached at matt.yan@globe.com. Follow him on Twitter @matt_yan12. Tonya Alanez can be reached at tonya.alanez@globe.com. Follow her on Twitter @talanez.