DALLAS (CBSDFW.COM) — Two men and one woman remained hospitalized Thursday in Dallas’ Parkland Burn Center. They are three of four firefighters rushed to the hospital after a suspected gas leak and explosion at the Highland Hills Apartments.

It’s still unclear what caused the explosion which left all the first responders with severe burns and long road to recovery.

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Thursday morning, September 30, the Texas Railroad Commission confirmed it is investigating any possibility of pipeline safety issues.

Dallas Fire and Police are conducting investigations to find out how the explosion happened.

The injured firefighters have not been identified, but Dallas Firefighters Association President Jim McDade told CBS 11 News at least two of them have more than 20 years of experience.

A Dallas Fire Rescue crew had arrived at the complex to check out a reported natural gas when the blast happened.

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(credit: CBSDFW.COM)

“We all very much so want to know what happened and what can we do in the future to prevent it,” McDade said.

None of the firefighters carry natural gas detectors. McDade says if they did it may have prevented some injuries.

“When we get these natural gas calls, we just kind of try to figure out where its coming from by the smell, which might not be the most efficient and safest way to do things,” he said. “If there’s equipment out here to help us in these situations where we can recognize the actual severity of it as we get there, then we need that equipment.”

(credit: CBSDFW.COM)

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The firefighters are surrounded by their families, friends and colleagues.

Kennedi Walker