SPRINGFIELD — A natural gas explosion rocked downtown Springfield on Friday evening, injuring 18 people after leveling a downtown strip club in the city's entertainment district, state and city officials reported.
None of the injuries were considered life-threatening, Springfield Mayor Domenic J. Sarno said.
Nine city firefighters, two police officers, and four gas workers were injured in the explosion on Worthington Street, Sarno said. A water-and-sewer worker as well as two other people were also hurt.
"This is a miracle on Worthington Street that no one was killed," Lieutenant Governor Timothy P. Murray said at a news conference near the site of the blast Friday night.
The explosion happened at 5:25 p.m., leveling Scores Gentlemen's Club, punching a large hole in the street, and blowing shards of glass and other debris through downtown streets.
A number of other buildings in the area were significantly damaged, authorities said.
"It felt like a bomb fell in front of the building," said Albert Fuster, 44, who lives close to the club. "All of the windows fell out, then the smoke came in. It shook me out of my seat practically."
It was "just a mushroom cloud of an explosion — big and orange,'' said Victor Bruno, who owns Adolfo's Ristorante in the district.
A line of more than a dozen ambulances remained on Chestnut Street, near the site of the blast Friday night where the sidewalk was littered with shattered glass.
The explosion blew out windows in several nearby buildings, including Allstar Insurance, which sits more than a block away from the center of the blast.
The area is a bustling entertainment and residential district.
It was quiet Friday, the day after Thanksgiving, although Bruno and other witnesses said it would have been crowded later in the night.
Calls were first made to report the odor of gas at Scores around 4:20 p.m. and gas workers evacuated the area.
As they were finishing their investigation about an hour later, the explosion occurred, according to Mark McDonald of the New England Gas Workers Association.
"It's a good thing the people were still evacuated,'' McDonald said. "If there were people in the building, it would have been a real catastrophe."
Stacy, a dancer at Scores who asked that the Globe only use her first name, said she had smelled gas in the building earlier this year. She said the owner of the club used to spray deodorizers to mask the smell.
"I've been smelling gas there for four months," Stacy said. "People would come in and say it smelled like gas."
A spokesman for the gas company, Columbia Gas of Massachusetts, said they and authorities were investigating why the building exploded.
"At this point the situation has been made safe,'' said Sheila Doiron, a spokeswoman for Columbia Gas, owned by NiSource. Doiron said Friday night that workers would remain on site for 48 hours monitoring the air, but they had not detected elevated gas levels since the explosion.
She said the blast occurred after workers shut off gas to the Worthington Street building. Gas and other safety workers were waiting across the street behind a truck for the building to vent when the explosion occurred.
Several city blocks were cordoned off with yellow tape Friday night as emergency responders and utility workers maintained a heavy presence around the site of the explosion.
Springfield Building Commissioner Steve Desilets said inspection teams would check buildings in the area Saturday morning, surveying to see if any structures will need to be demolished.
A Massachusetts Emergency Management Agency team set up a shelter at Springfield Central High School on Friday night, Sarno said. It was unclear who was using the shelter late last night.
The mayor, in his address to the news media, referenced the tornado that cut a swath of destruction across the city in June 2011.
"We're well-tested," Sarno said. "The city is resilient."
The blast comes less than a week after a Boston University-led study showed that Boston's aging underground pipeline system is riddled with more than 3,300 leaks.
While the vast majority are not considered a safety risk, the study underscored the explosion risk and environmental damage — the gas is a powerful greenhouse gas and can damage trees — that exists under older city sidewalks and streets. Study authors said any older city — Springfield is one — would have similar problems.
Robert Ackley of Gas Safety Inc., one of the coauthors of the paper, noted then that many leaks that are considered safe can grow to larger ones that can endanger people.
Bill Fiore, 23, who owns Allstar Insurance, said he heard a series of loud noises around the time of the explosion, but thought little of it.
"There's been a lot of shooting lately, so I thought it was someone shooting," he said. "It sounded like a machine gun."
Beth Daley of the Globe staff and Globe correspondent Melanie Dostis contributed to this report. Anderson can be reached at email@example.com. Young can be reached at firstname.lastname@example.org. Sampson can be reached at email@example.com.