Camp Mystic, a 99-year-old Christian summer camp for girls in Texas Hill Country, was hosting 750 children this week when catastrophic flooding struck the Guadalupe River early Friday, leaving at least 20 children missing.

Founded in 1926, Camp Mystic operates two sites along the river in Hunt, Texas. It has long billed itself as a place for girls to grow spiritually and “develop outstanding personal qualities and self-esteem,” according to its website.

Each summer, Mystic challenges its campers to “be a better person for being at Mystic,” and to “let Mystic bring out the best in them.” The camp’s website emphasizes life-long friendships and a “wholesome Christian atmosphere.”

The flash floods killed at least 24 people in Texas Hill Country. The identities of the deceased and missing have not yet been officially released, but dozens of families shared in local Facebook groups that they have received phone calls from safety officials saying their daughters had not yet been located.

Camp Mystic said in an email to parents of the roughly 750 campers that if they have not been contacted directly, their child is accounted for.

Dick and Tweety Eastland, the current owners, have been involved with Camp Mystic since 1974. The camp has remained in the same family for generations, dating back to the 1930s.

A video on the Camp Mystic website shows a sprawling campus by the river, with footage of girls playing in the water, rowing boats, riding horses and playing tennis.

The flash flooding began around 4 a.m. Friday after heavy overnight rain swelled the Guadalupe River. Water swept into Kerr County and surrounding areas with such speed that officials say they were unable to issue evacuation orders in time.

“This happened very quickly, over a very short period of time, that could not be predicted, even with the radar,” said Dalton Rice, city manager for Kerrville, the county seat. “This happened within less than a two-hour span.”

Bodies were reported to have been found in vehicles swept away from upstream areas.

The river had crested in Kerrville and Comfort by Friday evening, but downstream sections — including near Spring Branch — weren’t expected to peak until early Saturday. The National Weather Service projected a crest of 37.2 feet there, considered moderate flood stage.