Main Street is blocked off between Cross and Wall streets to traffic and pedestrians on Tuesday morning, police said.
"Officers reporting 2 underground explosions in the area of Main & Wall. No injuries reported at this time. Manholes dislodged as a result," said Chief Tom Kulhawik via Twitter @NPDChief at 8:49 a.m. Tuesday.
Personnel from the Norwalk Fire Department and Police Department are on the scene. Connecticut Light & Power is on the scene, investigating as well, with workers already working below ground as of 10 a.m.
"CL&P is on scene and working on the issue on Main, Appears to be an electrical issue and no evidence of any gas issues," Kulhawik said via Twitter.
The explosion shattered the windows of the nearby New York Bakery in central Norwalk, he said. That appears to be the only damage, Kulhawik said.
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