By Walt Hunter

PHILADELPHIA (CBS) — PGW officials say a break in a six inch cast iron gas main caused a leak leading to an explosion inside a two-story apartment house at 7912 Ardleigh Street in Chestnut Hill around 1:30 this morning.

So far, it’s not known what caused the natural gas leak, which is also being investigated by the Public Utility Commission.

“The Lord was looking out for us,” said Richard Jordan, who along with his wife and dog, escaped the blast as the floor of the first floor buckled, furniture began flipping upside down, and windows were blown out, shattering windows of cars parked across the street.

Upstairs tenant Paul McGinty also escaped unhurt and he helped neighbors get safely out of their shattered apartment.

None of the four people inside the apartment house suffered any injuries.

PGW says crews will now replace the main that broke.

The Jordans said while they are shaken and heartbroken by the loss of personal possessions, including an irreplaceable collection of hand-carved wooden ships, they are very grateful to have survived the natural gas explosion.

“It’s a miracle,” Mr. Jordan concluded,”It’s just amazing.”

Among the factors expected to be considered as officials investigators search for the cause of the main leak: the bitter cold and the age of the main itself.