Philadelphia, PA – Eight people were injured in Philadelphia on Monday in what police said might have been a natural gas explosion that caused the collapse of one house and the evacuation of about 70 homes.

The injured included a man who was in critical condition and a child who had suffered minor injuries, Philadelphia Fire Department Deputy Chief Robert Coyne said.

An eyewitness told the CBS News TV station in the city that a child had to be thrown from the house in south Philadelphia into the arms of a firefighter.

Residents reported a strong smell of natural gas after the blast and Philadelphia Gas Works crews shut off gas to the area, utility spokeswoman Melanie McCottry said.

Hundreds of people watched as emergency workers and firefighters went about clearing 15 feet (4.6 meters) of rubble and debris that spilled onto the street from the collapsed home.

One resident of the neighborhood, Diane Schaffer, said the smell of gas had permeated the area since early Monday morning. After the explosion, she put her son and a neighbor’s daughter in her car and fled the area.

“I could hear a guy saying, ‘Help me, help me,’ but when I looked back, I saw two guys running towards him, so I felt okay about leaving,” Schaffer said. “We just sped off.”

Early last month a four-story building under demolition in the city collapsed, killing six people and injuring 14 as it fell onto an adjoining Salvation Army Thrift Store, burying shoppers in debris.