Two weeks after Boston firefighters responded to several manhole fires in the city, two more explosions happened in the city’s Financial District on Thursday morning. Two individuals were reportedly injured in the latest incident, with one woman transported to Tufts Medical Center after suffering flash burns.
Amateur video shows flames shooting up out of manholes for a brief moment around 8:40 a.m., producing plumes of smoke and shattering adjacent windows. Authorities suspect the explosions were the result of underground pressure, as Deputy Fire Chief Brian Tully told NBC10 Boston:
The fiery blasts were believed to have been caused by over pressurization underground, Tully said. One manhole cover was found several feet away from the opening; the woman who was injured was burned, possibly by steam, but she was able to walk to an ambulance.
“When we’re using a ton of electricity and power, the equipment’s just being overused, overtaxed,” Tully said, adding, “I believe the energy system in our city is safe.”
Buildings along High Street, where the explosions occurred, were evacuated, while high levels of carbon monoxide were reported in the area afterward. Utility crews arrived to check for natural gas leaks, per the Boston Globe, and positive pressure fans were brought in to vent the carbon monoxide outside of the buildings’ interiors. Nearby on-ramps to I-93 were closed for about two hours following the blasts.
Manhole fires aren’t as unusual as they might seem. A similar explosion happened in Times Square two months ago, sending crowds running. In that case, Con Edison determined the cause to have been a cable fire stemming from the wires’ insulation igniting.
Witnesses in Boston were understandably alarmed in the moment, with one individual working nearby telling the Globe “it was just terrifying because we didn’t know what was going on at the moment. It really sounded like a bomb.” Another believed they saw a lightning strike immediately before the first explosion:
“I was startled because … it was clearly a lightning strike,” said [Carmen] 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.”
Boston electricity supplier Eversource, however, does not believe today’s incident had anything to do with lightning or, in the deputy fire chief’s words, “overtaxed equipment.” Per the Globe:
Eversource spokesman William Hinkle said the affected manholes belonged to the utility and that no Eversource employees were working there at the time. The cause of the manhole explosions is under investigation by Eversource along with other utilities and the fire department, Hinkle said.
“The incident this morning was not in any way related to overloading of the electric system, and we have not received any indication that lightning was involved,” he said. “Our team continues to work with local officials and other utilities conducting an investigation into the specific cause and other details.”
Eversource says it plans to share the findings of its investigation with the Department of Public Utilities.