Pennsylvania ? Natural gas explosions at Mohawk and S. Delaware streets in Allentown on Saturday afternoon leveled three homes, likely destroyed another and caused

$1 million in damage.

There were no serious injuries, according to officials.

“We were fortunate,” said Allentown fire chief Scott Lindenmuth.

At least four families were left homeless. Some weren’t home when the explosions occurred at 1:28 p.m. Others smelled gas, ran outside and pounded on neighbors’ doors to warn them to get out.

One neighbor rolled out of a second floor window as his house was collapsing, said resident Crystal Mack.

Mack said the explosions were caused by a gas leak that originated in her home at 789 Mohawk St. A UGI subcontractor was working on a gas meter in her home just before the explosions occurred.

After the blast, nearby neighbors were evacuated to Allentown’s South Mountain Middle School.

“All I heard was a big boom,” said Holly Ache, who lives on S. Delaware Street, three houses south of the intersection. “My whole house just shook. My windows broke.

“I went out the front door and I looked down the street and the houses were gone. They blew up.”