Jessica Leigh Hester is a former senior associate editor at CityLab, covering environment and culture. Her work also appears in the New Yorker, The Atlantic, New York Times, Modern Farmer, Village Voice, Slate, BBC, NPR, and other outlets.
Yet another thing to blame on snow and ice.
Winter street scenes can be pretty bleak. There are the mean, sneaky puddles that look shallow, but are secretly deeper than most inland lakes. There’s yellow snow. And, weirdly, there are lots of exploding manholes.
That’s not a euphemism. Across New York City, in particular, lots of manholes—more than 400 in the week following Winter Storm Jonas—are bursting into flames.
It happens when melting snow mixes with salt and floods underground electric structures, eroding the insulation between them, a Con Edison spokesperson explained to NBC News. That’s the recipe for an inferno.
Time Out reported that the blast can also hurl the 300-pound covers up to five feet in the air.
These plumes appear to be an annual menace. Back in 2011, the Huffington Post marveled at the fact that some locals seemed relatively blasé about the yearly tradition of fiery geysers. That same January, the New York Times remarked that it was “a risky season to be near a manhole.”
It’s not just a New York phenomenon. In 2014, the Telegraph reported a blaze in London, and speculated that it was correlated with the “wettest winter on record.” Throughout the U.K., there were 64 incidents of manhole fires in the first half of 2014, compared with nine in 2011.
Also, Science noted that “D.C. manholes have a tendency to blow up,” though these explosions may be due more to excess methane than precipitation. Researchers from Duke mapped gas leaks around the District, and detected methane concentrations 50 times higher than average. (In some places, the concentration was as high as 100,000 ppm; anything above 40,000 is considered dangerous.) The scientists ventured a guess that this gas might be the culprit in the average of 38 manhole incidents around the capital each year.
So far, no one seems to have been injured in this year’s edition of man vs. manhole, though some bystanders are—understandably—pretty shaken up. Still, since electrical lines can be corroded in the explosion, these incidents can cause widespread power outages, NBC noted. More than 2,000 homes across New York lost power as a result of this week’s fires.
A Con Ed spokesperson assured the Times that the company had altered the manhole design in the hopes of curtailing the flames through better ventilation. “We’ve taken great pains—we’ve modified the covers to manholes to lessen the impact,” he said.
Hopefully so. But don’t take any chances. Better safe than smacked in the face with a manhole cover. Wherever you are, if you happen to see smoke billowing out of a manhole, get outta Dodge and call the power company right away.