Two people were killed and at least 20 were injured in an explosion Tuesday afternoon at a nursing home in Bristol, Pennsylvania, officials said.

During a news conference, Pennsylvania Gov. Josh Shapiro said that two people had died. 

Bristol Township police later increased the death toll to three. However, Police Chief Charles Winik told CBS News Philadelphia late Tuesday night that one of the patients had been resuscitated at a hospital and survived.

The wounded victims were transported to five area hospitals. Everyone has been accounted for, Winik told reporters.

First look from the air at damage after Bristol, Pa. nursing home explosion

Chopper 3 flew over the scene in Bristol Township on Wednesday morning – you can see it on our YouTube channel.

Bristol Township Fire Chief Kevin Dippolito said it's believed that a gas leak led to two explosions and a fire.

According to a PECO spokesperson, crews responded to reports of a gas odor at the nursing home shortly after 2 p.m. Eastern Time. 

"While crews were on site, an explosion occurred at the facility. PECO crews shut off natural gas and electric service to the facility to ensure the safety of first responders and local residents," the statement reads.

"It is not known at this time if PECO's equipment, or natural gas, was involved in this incident," PECO said later Tuesday night.

Part of the building collapsed. Officials say a reunification site was set up at Truman High School in Levittown.

Two people were rescued from the collapsed part of the building, Dippolito said.

Shapiro praised the work of firefighters and other first responders from around the region who raced to the scene.

"They were quite literally climbing up ladders, handing individuals in this nursing home to police, who were at times carrying two people on their back to safety," Shapiro said.

New owners took over the facility earlier this month, Shapiro said. The state Department of Health visited the home on Dec. 10, and a plan to upgrade the facility was put in place, he added.

Bristol is located about 20 miles northeast of Philadelphia.

"To the Bristol community: I've got your back, and I'll be with you soon," Shapiro said earlier in a post on social media.