An explosion Wednesday that ripped through a cafeteria popular among senior citizens knocked diners out of their chairs, tore up sections of the concrete floor and shattered all the windows, witnesses said.

Irene Williams, 29, said she was sitting in the lobby of the Colonial Cafeteria when the late-afternoon explosion threw her to the floor."I thought it was an earthquake. Glass went everywhere," she said.

Glass and other debris were scattered down the block.

The explosion was under investigation. A worker at a nearby business said he smelled natural gas.