13 dead in Pennsylvania house fire

At least 13 people died and two were injured in Philadelphia, Pennsylvania, Wednesday morning after fire broke out in a three-story rowhouse that has been converted into an apartment building, local authorities said.

The Philadelphia Fire Department said on Twitter that its firefighters arrived at the building located on the 800 block of North 23rd Street at 6:40 a.m. local time and found heavy fire coming from the second floor of the building. It took 50 minutes to put the fire under control, but the scene is still active, it said.

Philadelphia Fire Deputy Commissioner Craig Murphy told a news conference that seven of the 13 people killed were children, calling the incident "probably one of the worst fires I've ever been to." He said there were four fire detectors in the building but none of them were operating.

Murphy said there were 26 people in the building when the fire broke out, and that the number of deaths could increase as the home was searched. Firefighters said two people were injured and in critical condition.

"It's not necessarily considered suspicious, but we have all hands on deck because of the magnitude," Murphy said.

"This is without a doubt one of the most tragic days in our city's history -- loss of so many people in such a tragic way," Philadelphia Mayor Jim Kenney said at the start of a news conference.

Investigators are still trying to find out the origin and cause of the fire. Murphy refused to elaborate on the details of the ongoing probe led by the Philadelphia Fire Marshal's office.

The CNN quoted the Philadelphia Department of Licenses and Inspections as saying that the structure was legally subdivided into two apartments since the 1950s. The building is estimated to have been built in 1920, CNN reported, citing property records.