NEW YORK (CBSNewYork) — Two manholes exploded on the Upper East Side on Monday morning.

The first went up at around 10:30 a.m. at 75th and 2nd Avenue. A short time later, the second exploded a block away on 76th Street.

The FDNY, which responded to the scene along with representative from Con Ed, later told CBS2’s Hazel Sanchez that street salt that had accumulated due to the tough winter New York City experienced likely damaged underground electrical wires, causing the explosions.

“Usually the snow, the run off, the melt, the salt, it corrodes the wires in the manholes and causes an electrical problem down there,” FDNY Battalion Chief Mark Rosenbaum said.

Two minor injuries were reported. 

Witnesses who heard the explosion told CBS2’s Sanchez they were surprised no one was seriously injured.

“I heard a big bang and it must have lifted me up a few inches off my chair,” one man said. “I was thinking about the Middle East. I was thinking about bombs. It was the first time I’ve ever heard anything like that before in my life. Very loud. Very effective.”

“I heard the first one and I thought there’s so much construction going on around here I figured OK it’s something that happened in the building that they’re working on. And then I heard the second one and I heard the fire engines coming,” said a woman. “I heard this big blast. I knew it was an explosion, but I just didn’t know where from. And then I looked out the window and there was a car going in the opposite direction, because the car had been over the explosion.”

The basement of a nearby building and several businesses were evacuated due to high levels of carbon monoxide, the FDNY said.

The explosions caused traffic changes in the area. Click here to check current conditions.