The remains of five employees who were reported missing after an Oklahoma rig explosion on Monday have been recovered, officials said during a news conference Tuesday.

The search for the workers began around noon after the drilling site became stabilized, Pittsburg County Sheriff Chris Morris said.

Earlier Tuesday, authorities announced that the employees were presumed dead and the search morphed into a recovery mission.

"Our hearts and prayers go out to the families that were involved in this rig explosion yesterday," Morris said at a news conference.

Morris identified the employees as: Josh Ray of Fort Worth, Texas; Matt Smith of McAlester, Okla.; Cody Risk of Wellington, Colo.; Parker Waldridge of Crescent, Okla.; and Roger Cunningham of Seminole, Okla.

The sheriff added that it's been a difficult 24 hours since the blast occurred 8:45 a.m. on Monday, with deputies and others tasked with the difficult chore of notifying families of those lost.

"I think you can imagine, they're not doing well," Morris said Tuesday. "No law enforcement officer likes to do that. The family not knowing and feeling empty about where their loved ones are, it's a tough situation."

Three of the workers were employed by Houston-based Patterson-UTI Energy Inc. Company president and CEO Andy Hendricks pledged a full investigation into the explosion.

"We want to learn from this," Hendricks told reporters. "We don't want this to happen again for anybody in our industry."

An initial report into the deadly explosion, released by the Oklahoma Corporation Commission, indicated that there was an uncontrolled release of gas that caught fire. A worker at the scene was said to have tried to shut down the well, but they were unsuccessful.

Authorities said the men were at a depth of 13,500 feet drilling to 17,000 feet when the blast took place, FOX25 News reported.

OKLAHOMA RIG EXPLOSION LEAVES 5 MISSING, EMERGENCY OFFICIAL SAYS

Sixteen people who were on the site at the time of the blast escaped without major injuries. One person was airlifted to a hospital for treatment.

The explosion about 100 miles southeast of Tulsa sparked several fires and sent thick black smoke into the air. The derrick, a towering metal structure above the well, also collapsed.

Fox News' Katherine Lam, Matt Richardson and The Associated Press contributed to this report.