Officials said an early morning fire in a north Philadelphia row home claimed the lives of three children and one adult.
Fire crews were called to the two-story residence in the Kensington neighborhood shortly after 2 a.m. Sunday and found heavy fire coming from both floors.
Three children were found dead, and a man reported unaccounted for was also later found deceased, officials said. The names of the victims and other details about them weren't immediately released.
One person who jumped to safety was taken to a hospital. The fire was declared under control just before 2:30 a.m. Sunday. Firefighters had found no evidence of working smoke alarms in the building, officials said.
The cause of the blaze is under investigation and the city medical examiner's office will determine the cause and manner of death of the victims.
Five days into the new year, a fire in a duplex north of the city center near the Philadelphia Museum of Art killed a dozen people, including nine children—the deadliest blaze in the city in more than a century.
Fire Commissioner Adam Thiel noted the earlier tragedy and said a total of 17 fire deaths had occurred since the beginning of the year before four deaths were added Sunday.
In addition, he said, 38 people had been injured and more than 312 families had been displaced so far this year.
"Fires are burning hotter and faster than ever before," he said, saying crews used to have perhaps 10 minutes before the phenomenon of flashover—simultaneous ignition of the contents of a space producing 800- to 1,000-degree temperatures—but modern furnishings and fixtures now allow flashovers in as little as a minute.
"All of us standing here swore an oath to do everything we can to protect lives and property everywhere we can do it. For us, the worst possible thing is to not be able to save a life," Thiel said.