Officials still working to determine cause of Port Richmond explosion that injured 5

PHILADELPHIA (WPVI) -- Investigators are still working to determine what caused a rowhome to explode on New Year's Day in Philadelphia's Port Richmond neighborhood.

The blast leveled two homes and damaged more than 40 others along the 3500 block of Miller Street.

On Wednesday, PGW said it did not find any natural gas leaks in the area, but it still needs to test gas lines directly in front of the home that exploded.

SEE ALSO: New Year's Day explosion rocks Port Richmond, injures 5; investigation underway

Investigators are still working to pinpoint the cause of the blast that leveled homes in Port Richmond.

PGW released the following on its investigation:

• On Jan. 1: PGW conducted state-of-the-art leak detection surveys on all underground natural gas mains and service pipe on Miller, Gaul, Venango, Atlantic, and Belgrade Streets. Mains and service pipes were found to be in good operating condition and PGW identified no natural gas leaks on any surveyed PGW natural gas infrastructure. Each leak survey and safety check were conducted in coordination with the onsite Pennsylvania Utility Commission Safety Division.

• On Jan. 2: PGW began testing the PGW pipeline infrastructure that runs from the main in the roadway to the meter inside each impacted property. This test investigates the integrity of the pipe. The first property tested was 3546 Miller. The service pipe at 3546 Miller was found to be in good operating condition, passed the pressure test, and no leaks were found.

• On Jan. 3: The service pipe at 3548 Miller was tested and found to be in good operating condition, passed the pressure test, and no leaks were found.

Five people were injured in the blast including a 64-year-old woman, a 47-year-old man, a 44-year-old woman, and two other males whose ages are not known at this time.