NEW YORK (CBSNewYork) — Witnesses at the scene of a massive steam pipe explosion in the Flatiron District say it was like a volcano erupting right underneath Fifth Avenue.

“I heard a really loud boom and then a steam noise coming out,” evacuated resident Andrew Glasser told CBS2’s Janelle Burrell. “And we were told to evacuate our building.”

Photos: Massive Steam Pipe Explosion In Manhattan’s Flatiron District

Glasser was asleep when the high-pressure steam pipe exploded around 6:40 a.m. Thursday on Fifth Avenue near 21st Street.

“I’m just in shock,” he said. 

Some witnesses said the electricity went off for a few seconds just before the giant plumes of white steam came billowing out of the ground.

“Not only did the steam line burst, but it caused a disruption of a gas line, a water main and some electrical power,” said Fire Commissioner Daniel Nigro.

The pressure from the pipe, which was installed in 1932, also caused the pavement around it to crumble.

“We saw a good amount of chunks of asphalt,” said witness Miro Bajlo.

“There were massive plumes of steam coming out, rising up against the building,” said witness Mike Wynn.

“I assured some old ladies, I said don’t walk near the manhole covers, there’s an explosion ’cause no one really knew,” said Bronx resident Patty Marsibilio.

Firefighters evacuated 49 buildings while others were told to shelter in place, including Sunny Agis, the superintendent of the Flatiron Building.

Agis spoke to CBS2 by phone from inside the building while watching the steam rise hundreds of feet.

“Like lava coming out of the earth, it was crazy,” he said. “The building is locked off. They’re not letting anybody in or out.”

Asbetos testing found the potentially cancer-causing substance in the aging pipe but not in the air, which is safe to breathe.

As a precaution, the FDNY has set up decontamination tents for crews and for anyone who have been in the area at the time of the explosion. Con Edison is urging anyone in the area at the time of the blast who may have been covered in any debris to bag their clothes and take a shower.

Meanwhile, residents and employees in the area that is shut down are now waiting to hear when they’ll be able to return.

“I just hope everything is OK,” said Glasser.

Getting around the area means showing ID and dealing with barricades, CBS2’s Marc Liverman reported.

“I think it’s a pain in the butt right now,” one woman said.

“I was just walking up, I live just five blocks north, and I saw the smoke. I work two blocks south of this, so I can’t get anywhere,” said Sarah Anissipoeur.

“I’m supposed to be in the building right now doing some maintenance, but I don’t really think I’m going to get down there,” William Aumick said.

It’s a blow to area businesses, too. Some are dealing with no power and no customers.

“It’s going to have a big impact. We’re really keeping an eye on the ground floor businesses in particular,” said Jennifer Brown, of the Flatiron 23rd Street Partnership. “If many of them have to be closed for multiple days, that’s a huge loss of business impact. We have to work with the city. They have a really great emergency response unit out of the department of Small Business Services. So they’ll be going around and really assessing what the businesses need and what types of resources we can help out with.”

Eight people suffered minor injuries in the blast.