"I was inside the restaurant, and (I heard) a big, big explosion. Whole building was shaking like, like an earthquake," he said.
When he went outside to see what had happened, he saw smoke.
"It really was scary, and I look in to my neighbor. The windows came down, and I have to go look around inside and see if my neighbor, she was OK. And she was really lucky, she was inside, all the way, up inside the store," he said.
Others on the scene agreed: Pedestrians, homeowners and business-owners are all very lucky, because on any other day, if the weather were better and more people were around, injury would have been far more likely.
PGW crews are measuring for gas leaks. Firefighters are going in and out of neighboring businesses. Crews are uncertain whether the explosion involved any PECO electrical equipment.
A coffee shop across the street also had damage to its window. Some businesses were evacuated due to high levels of carbon monoxide.
A PECO spokeswoman reported there are no customers affected, but 20th Street is shut down between Market and Chestnut streets.
This incident was not far from where a sinkhole opened up recently. Whether Tuesday's explosion was weather-related or had anything to do with the repairs of that earlier sinkhole is unknown.