Since Sunday, Con Edison has responded to over 200 manhole explosions throughout the city. So far at least one person has been hospitalized: a 71-year-old man who was struck in the head while walking his dog in Park Slope Monday morning, and a second person was injured.

Other incidents of manhole explosions include one on Monday night, where residents of Washington Heights had to be evacuated due to an explosion causing a carbon-monoxide leak. A similar situation happened Tuesday afternoon in Park Slope, as another manhole explosion caused residents to stay inside a city bus for six hours while firefighters dealt with the fire and gas.

Why are so many manholes in the city are exploding? The New York Daily News has the explanation:

“We tend to see an elevated response to manhole conditions — fires, elevated carbon monoxide readings, and smoking — after a heavy snowfall,” an FDNY source explained Tuesday.

“We oversalt the roads and when it melts it goes into the manholes and the chemicals erode the wires, which catch fire.”

On the positive side, manhole explosions in the city have dropped from last year, which saw more than 1,100 cases in January, compared to 977 last month.

A Con Edison spokesman told NBC New York that the utility company “is constantly working on new technology to limit the number of manhole fires.”

(Photo: Beth Burdick)