The cause of a deadly fire is under investigation after seven people were killed and several others injured in an explosion at a chocolate factory in Pennsylvania, police and city officials said.
The explosion occurred Friday evening at the RM Palmer Company in West Reading, located about 60 miles northwest of Philadelphia. It caused destruction to one building nearby and damaged another. Images of the scene showed smoke and flames billowing from the factory.
One person had been found alive overnight in the rubble, giving first responders hope that more survivors would be rescued, though two additional bodies were recovered from the rubble at the site of the factory Sunday night, West Reading Police Chief Wayne Holben said at a press conference.
Tower Heath said earlier its hospital in West Reading initially received 10 patients from the explosion.
The victims killed in the incident ranged in age from 30 to 63 and were all from Pennsylvania.
They were identified by the Berks County Coroner's Office as Michael Breedy, 62, of Marion Township; Diana Cedeno, 44, of Reading; Domingo Cruz, 60, of Reading; Susan Halvonik, 63, of Upper Providence Township; Judith Lopez-Moran, 55, of Reading; Xiorky Nunez, 30, of Reading, and Amy Sandoe, 49, of Ephrata.
"Forensic medical examinations are continuing to determine the cause and manner of death for all victims," the coroner's office said.
An investigation to determine the official cause of the fire will be conducted, officials said.
"In the initial incident report from Berks County to PEMA, a reference to a gas leak was included. It is really important to note that incident reports from counties are a snapshot in time of the understanding of the incident at the time the report was made," Ruth A. Miller, PEMA's communications director, said in a statement.
The National Transportation Safety Board on Tuesday said it's launching a safety investigation looking into the natural gas explosion and fire.
West Reading Mayor Samantha Kaag issued an emergency declaration Saturday to access more resources for emergency responders on the scene.
Kaag, a former volunteer firefighter, called the incident "pretty scary," adding that it was so strong it pushed a building back 4 feet. The mayor said the factory building was "pretty leveled" and crews will "probably" be working through the weekend to clear the debris.
In a statement Saturday, RM Palmer said it is "devastated by the tragic events."
"We have lost close friends and colleagues, and our thoughts and prayers are with the families and friends of all who have been impacted," the company said. "We are sincerely grateful for the extraordinary efforts of all of the first responders and for the support of our Reading community, which has been home to our business for more than 70 years."
The company said it will continue to coordinate with local and national agencies to assist in the recovery process. It added that it has been unable to get in touch with the families of impacted employees at the time due to downed communication systems but "will be providing additional information and making contact with employees, impacted families, and the community as soon as possible."
Pennsylvania Gov. Josh Shapiro was on site Saturday surveying the damage and "to pledge our support as the community recovers," he tweeted.
A woman who lives next to the chocolate factory has filed a lawsuit accusing the company of negligence that led to the fatal explosion.
RM Palmer did not immediately respond to ABC News' request for comment about the lawsuit.