On Sunday February 28th, an exploding manhole rocked Midtown East, NYC, around 7:30 AM. While we'd like to say this is a rare occurrence, that is unfortunately not the case in New York City. According to a special report in 2020 by The City news, between 2009 and 2018 the city logged nearly 4,000 such explosions, with the NY Fire Department responding to more than 45,000 emergency manhole incidents.

For those not familiar with New York manhole explosions, these are primarily a winter event caused when rain or snow melt mixed with corrosive salt seeps underground onto aging, or old and frayed underground wires that have already been subjected to caustic chemicals, gnawing rats, or just simply decay.  Because these cables carry as much as 13,000 volts of electricity, they can ignite insulation made from paper, lead, and rubber. The insulation smolders and catches on fire, releasing gases. The pressure from the gas builds up inside the manhole, and the electrical wires arc like a bolt of lightning and ignite the gases, causing a powerful explosion. For more detailed information, see How Stuff Works.

The city of New York has 246,000 manholes and service boxes in its underground system, serviced by Con Edison. Manhole covers typically made of cast iron weigh between 85-300 pounds, so when the flames cause the built-up manhole gas to combust it can send these massive covers skyrocketing anywhere from 1 to 50 feet. Along with that, the concussion from the explosion of gas damaged nearby vehicles and buildings. The greater the combustion, the greater the damage.