The July 4 tragedy at Camp Mystic outside of Hunt, Texas, was concentrated at just two cabins where Mystic’s youngest campers bunked and where a confluence of rising water from the river and a normally quiet creek swallowed the buildings before the girls could escape.

Of the camp’s 28 deaths, 15, including two teenage counselors, were at a cabin known as Bubble Inn, where no one survived, according to a new accounting of the fatalities by the camp. Eleven of the other girls who died had been in the cabin called Twins, a pair of adjoining buildings, said Jeff Carr, a Camp Mystic spokesman.

Another fatality was the camp’s longtime director, Dick Eastland, who died trying to rescue campers from Bubble Inn. Only one death at the camp — a camper from a nearby cabin called Jumble House — was unconnected to Bubble Inn or Twins.

The new accounting underscores how focused the raging waters were at the nearly 100-year-old Christian retreat in the Texas Hill Country. The two beige stone cabins were enveloped by floodwaters that pushed in from opposite directions in the pre-dawn darkness, probably spawning eddies, trapping campers and confusing anyone who tried to save them from the swirling pools, experts say.

A dozen Twins campers and their four counselors survived, Mr. Carr said. But most of the 8- and 9-year-olds in the two cabins, nestled among pecan and live oak trees, did not.