Three children were burned when a boat exploded and caught fire in Calvert County. (Courtesy of Maryland Natural Resources Police.)

Three children were airlifted to the hospital with burns after a boat exploded and caught fire Saturday on a creek in Calvert County, a spokeswoman for the Maryland Natural Resources Police said.

The 20-foot Wellcraft recreational boat caught fire about 100 yards from shore on Mill Creek in Lusby, Md., shortly after the boat launched with five people aboard around 11:30 a.m, said the spokeswoman Candy Thomson. All five managed to make it to shore.

Two of the children suffered severe burns during the incident, which burned the boat down to the water line, Thomson said. The children, ages 3, 8 and 9, were rushed to D.C. Children’s Hospital.

As of Saturday evening, Thomson said the 3-year -old was in critical, but stable condition. The 8-year-old was under observation and the 9-year-old was being treated for first and second-degree burns. The children’s names were not released.

The children’s mother, Tamara Johnson-Harmon, 27, of Lusby, and father, Devyn James Harmon, 31, of Lusby, were also on board, Thomson said.

Thomson said the cause of the explosion and fire is still under investigation, but said the boat burned and sank very quickly.

“Witnesses said they heard a boom and when they looked the engine cover was up in the air,” Thomson said. “The boat burned and sank very fast.”

The boat was launched out of a private slip in the 12500 block of Rousby Hall Road. Mill Creek , where the explosion occurred, is a tributary of the Patuxent River.

Thomson said the Prince Frederick Volunteer Fire Department responded to the incident and a local fire marshal will investigate the cause of the blast.