
Manholes weaponized this month, with more than 300 exploding in flames since last week’s Snowmaggedon and one cover even hitting a 71-year-old man on the head as it flew through the air. It turns out the answer to why these things keep happening is quite simple: salt. According to CBS News, icy weather means that salt sprinkled on roads eventually runs down under the manhole covers, where it has a chance of coming into contact with exposed copper wiring, sparking, and igniting various trapped underground gases. Slotted manhole covers should eventually alleviate these instances a bit, but, for now, Con Ed underground operating supervisor Al Munro says battling these fires is like “going into battle.”