Family members told 5 on Your Side that over 85% of 18-year-old Dontea Anthony Jr.’s body is burned.

ST. LOUIS COUNTY, Mo. — The 18-year-old who was critically injured in a home explosion in north St. Louis County on Monday was in the basement of the home at the time of the blast, a family member told 5 On Your Side.

Dontea Anthony Jr., 18, was the only member of the family inside the home at the time of the explosion. After the explosion, he had to escape the home through flames, which left him burned on 85% of his body. He was rushed to an area hospital with critical injuries.

In a Tuesday evening news conference, St. Louis County Police Chief Kenneth Gregory said the explosion was likely caused by natural gas, but the cause was still under investigation. Officials ruled out anything criminal as a cause.

RELATED: ‘Felt like an earthquake’: Major explosion injures 5, damages more than 20 homes in north St. Louis County

Dontea’s twin brother recently started at Maryville on a full-ride track scholarship; his mother was out for a jog, and his father was at work. Dontea was a recent graduate of Hazelwood Central.

A GoFundMe page started by Dontea’s aunt said he has “a very challenging road ahead of him,” and that the family needs help recovering and rebuilding after Monday’s explosion.

The page has a goal of $10,000, with all the proceeds going to the Hardy-Anthony family. To donate, click here.

Reports of the explosion on Evan Aire Drive started coming in shortly after 9 a.m. Fire crews arrived to find five homes on fire, said Black Jack Fire Protection District Assistant Fire Chief Paul Peebles.

The explosion destroyed or damaged more than 20 homes. Many residents in the area were ordered to evacuate their homes after structural engineers assessed buildings in the neighborhood.

Following officials’ Tuesday announcement that the explosion was likely due to natural gas, Spire released a statement reiterating that it found no issues with its infrastructure “leading up to” affected houses and that it had received no reports of a gas odor or of recent digging in the area. 

“We take our responsibility for safety very seriously and we’re committed to keeping our customers, employees and communities safe. We’ll continue to support the fire department and applicable regulatory bodies in a full investigation of the incident,” Spire said.