MALDEN (CBS) -- National Grid is investigating the cause of at least two manhole explosions Sunday afternoon in Malden.
Initially, National Grid said a transformer explosion was the culprit, but the utility and the Malden Fire Department are continuing their look into the reasons why the explosions occurred.
The explosions happened on Main Street near Malden High School. Malden Fire said at least four manholes exploded or caught fire.
"At first, I saw this pitch black smoke billowing out," one witness said. "We heard the explosion, and then when we came out we saw the black smoke and then the fire."
The original call came in for a manhole fire in the area of Main and Florence Streets at 12:30 p.m. Sunday.
"And then I saw a little bit of fire coming out and then, it just got bigger and bigger and bigger - about the size of a car," another witness said.
"We had an initial report of a manhole explosion. So when we pulled up, we had heavy smoke coming from one manhole in front of 555 Main Street. We summoned National Grid. Not long after that, a second and subsequently a third and fourth manholes also exploded due to a build up of obviously combustible gases on the street," Malden Deputy Fire Chief Bill Sullivan said.
Twenty-five to 30 people who live and work in the adjacent buildings were evacuated after at least two manholes exploded.
Nobody was hurt in the fire or explosions. The MBTA sent a bus to temporarily house those evacuated.
Once the fires were extinguished, Malden firefighters remained on the scene to monitor any hazardous gas buildup in the basement of buildings in the area, which there was none.
Approximately 70 customers were affected by the outages. Power was restored around 3 a.m. Monday.
Candles burned at Bala Ji Grocery. And inside, the aisles and shelves were dark. No business on a Sunday, but they're thankful nobody was injured.
"Yeah, it was a little bit hectic because the customer was inside and at that time you don't understand what is going on. So the first one that blew and then there was a fire inside and then the second one it blew," Ani Vyas of Bala Ji Grocery told WBZ.
WBZ NewsRadio 1030's Kim Tunnicliffe reports
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