Imagine walking down a bustling street when suddenly, smoke and heat start billowing out of manholes. That’s exactly what happened on Newbury Street in Boston, leaving residents and businesses in shock. But here’s where it gets controversial: Was it an explosion, or just an electrical failure? Eversource, the local utility company, insists it was the latter, but the debate is far from over.
On Tuesday night, an underground electrical cable failure caused chaos on Newbury Street, forcing the evacuation of multiple buildings after smoke and intense heat erupted from several manholes. According to Eversource officials, the issue stemmed from a single manhole near Dartmouth and Newbury streets, where a secondary electrical cable connection malfunctioned. Doug Foley, president of Massachusetts electrical operations for Eversource, explained that an electrical short in the manhole sparked a fire. The cable, made of copper and encased in a neoprene jacket—a durable, water-resistant material—was being repaired by crews on Wednesday.
The incident left 14 Eversource customers without power, though service was quickly restored, partially through generator power. Foley assured the public that the area is safe for pedestrians and drivers, despite ongoing repairs. Interestingly, the failure generated such intense heat and smoke that it vented through nearby manholes connected by underground conduits, though no damage was reported in those locations.
And this is the part most people miss: The Boston Fire Department described the event as “explosions” involving six manholes, but Foley disputes this characterization. “I wouldn’t consider it an explosion,” he said. “It was an electrical failure. The energy from the conductor went to the ground, producing heat and smoke—not an explosion by definition.” He added that loud sounds reported by witnesses were likely electricity discharging to the ground, a common occurrence in such failures.
This incident highlights the challenges of maintaining Boston’s aging underground electrical network, much of which lies beneath streets built long before modern utilities. Unlike overhead lines, underground cables are designed to operate in harsh conditions but remain susceptible to corrosion and wear. Foley noted that winter weather, particularly the recent snowstorm and subsequent snowmelt, likely contributed to the failure. Road salt and water seeping into manholes create a corrosive environment that degrades cable connections over time. Additionally, repeated heating and cooling cause cables to expand and contract, leading to wear and eventual breakdown.
These issues aren’t new. Over the past decade, Boston has seen a series of manhole incidents, some of which have launched heavy cast-iron covers into the air, causing injuries and property damage. In response, Eversource developed “energy-release” manhole covers designed to vent pressure while staying securely latched. Foley stated that the cover at the Newbury Street manhole remained in place during Tuesday’s incident, and Eversource claims no covers have been dislodged since the program began in 2022.
With approximately 45,000 manholes across Massachusetts, Eversource has prioritized upgrading dense urban areas like Boston and Cambridge. Foley reported that over 60% of locations have been upgraded, with energy-release covers installed in about 99% of Boston’s manholes.
But here’s the question that lingers: Are these measures enough to prevent future incidents? While Eversource’s efforts are commendable, the recurring nature of these failures raises concerns about the long-term sustainability of Boston’s underground infrastructure. What do you think? Is this a problem that can be fully solved, or are we destined to see more of these incidents in the future? Let us know in the comments below.
