The cause of Saturday night’s house explosion in Red Oak, Iowa has not yet been determined. Fire investigators have ruled out natural gas and a methamphetamine lab was not on the premises.

The blast occurred around 11:15 p.m., demolishing the structure. Two women hurt in the blast ran to a neighbor's home for help. The victims, 25-year-old Melissa Golden and 23-year-old Jill Kaczor, remain hospitalized in a Lincoln burn unit in critical condition.

They were visiting Golden's mother, who wasn’t home at the time.

"I heard the biggest bang you ever heard in your life,” says Bud Briggs. “I mean it was loud."

Loud enough to make neighboring houses shake. "I got to the door and all you could see was flames about 20, 30 feet in the air just going," says Briggs, who then saw the women emerge, their faces covered in soot.

The victims somehow managed to get out of the burning house and go to the nearby home of Briggs' sister, Carolyn Vanderhoof, where they knocked on the door for help. "While I was talking to 911 these two girls come on the porch. They were hysterical. They were screaming."

Vanderhoof says she can't imagine how they got out. Her brother lives a few houses down and felt the flames from his porch. "The heat was so intense, you wouldn't believe the heat," says Briggs.

He says Golden's mother was in Council Bluffs when she heard there was a fire on the block. She called him to find out what was happening. "I said yes, it's your house burning down to the ground right now. Just broke down and just bawled."

"My heart goes out to the whole family,” says Vanderhoof.

Neighbors say there were at least eight dogs in the house and that one died of smoke inhalation. The others got out okay.