A supermarket was destroyed by two explosions that erupted minutes after about 40 customers were evacuated because of the smell of gas.

Nine people injured in the explosions Monday were treated and released from area hospitals, said Scott LaGreca, a fire department spokesman.

"We could smell gas real strong," said Jack Hewitt, a cashier at the Super Buy Grocery on the city's west side. "We were opening the doors to get some air when it blew up. I was knocked into the street."

The force from the first explosion blew out one wall of the two-story building, crushing three cars in the parking lot. Another explosion followed seconds later, arson investigators said.