Caught on video: NYC sidewalk partially explodes

NEW YORK – Dramatic video captures the moment part of a sidewalk buckled in New York City after a manhole explosion. 
It happened at around 12:30 p.m. Friday on East 48th Street between Lexington and Third Avenues. 
Neighbors say it sounded like a bomb went off, and some buildings in the area had to be evacuated. 
The explosion was captured on surveillance video, which shows a woman with a backpack walking on the sidewalk when the explosion takes place, causing the sidewalk she’s standing on to pop up beneath her feet. Parts of the sidewalk that she had just crossed over went shooting up under a scaffolding. She managed to scramble to safety. 
Firefighters were already on the scene at the time of the blast, checking on reports of manhole fires nearby. 
Fortunately, no injuries were reported. 
“It was scary. Very scary,” doorman David Singh said. “We saw the whole pavement come up, the noise, and just ran away.” 
“There was smoke coming out of the manhole in the street, and then we smelled gas. And then, 10 minutes later, the whole sidewalk came up,” witness Rafael Maldonado said. 
“I heard this big explosion like a bomb – I am a military wife – and then all of this smoke, and you couldn’t see nothing,” Joan Mary Jacobs said. 
“They evacuated everyone out, out, out, and  started watering everything down,” 
Con Ed confirmed the manhole fire, and said they’re investigating the cause. 
A total of 12 units responded including 60 firefighters and EMS personnel. FDNY leaders said there were high levels of carbon dioxide in the cellar when they arrived. 
“We are assuming it might be gas stuck in between the sidewalk, and there could have been a leak. And since there is no ventilation underneath the sidewalk, it eventually went to explosive levels,” FDNY Deputy Chief Claude Hagen said. “Today, there was no high heat, no strain on the system. I am not sure exactly what caused this.” 
There was no structural damage, according to the FDNY, and the scaffolding the explosion happened under is still standing.