By J.D. Miles

DALLAS (CBSFW.COM) – Questions, fears and prayers after a mysterious explosion at a South Dallas apartment complex seriously injured eight people including four Dallas firefighters, Wednesday, Sept. 29.

One building at the Highland Hills Apartments partially collapsed and will be demolished.

There were reports of a natural gas leak at the time but Wednesday night, Atmos Energy insisted its system was working properly.

Sources told CBS 11 that two of the three firefighters are still hospitalized in intensive care with significant second-degree burns.

They are getting the best care in Parkland Hospital’s Burn Unit while the investigation continues into what led to the explosion.

All four injured civilians were released from the hospital by Wednesday night.

For the residents of the apartment complex who weren’t injured, it’s also been a traumatic time.

Paul Randall grabbed his 2-month-old grand baby and started running when it happened after 10:00 a.m.

“When I came outside I thought each unit was about to start blowing up so that’s why I started running up the hill,” said Randall.

His family is among 200 displaced from their units who are depending on the Red Cross for dinner and temporary housing.

“Wee don’t even know we’re gonna stay out tonight,” he said. “We don’t even know where we are going to lay our head tonight.”

Resident Lekeisha Williams suffered cuts from the blast which she says happened after Dallas firefighters responded to concerns about a natural gas odor and tried to break into a unit.

“One of the first responders, she went out there to the fire truck to get something out of there I guess to open the door to go in,” said Williams. “As soon as she did that to the door the apartment just blew up.”

Four firefighters were rushed to Parkland Hospital where they were initially listed in critical condition.

But the city’s fire chief revealed that they are all expected to survive along with the others injured.

“There is no such thing as a routine call and at any given moment the health and safety of our brave men and women can be placed at extreme risk,” said Chief Dominique Artis.

The City of Dallas promised an investigation in a statement.

Atmos energy is deflecting blame in a statement:

This morning, Atmos Energy was called by Dallas Fire-Rescue to the scene of an apartment complex on Highland Hills Drive in Dallas. After verifying that gas was shut off to the meter that supplies the apartment complex, our highly trained technicians began performing safety checks of Atmos Energy’s system. Atmos Energy has verified that our system is operating as expected, and we have found no indication that our system was involved.

The city is encouraging people interested in helping the affected families to donate to the Red Cross on the Dallas Foundation’s Disaster Relief Fund.