LITTLE ROCK, Arkansas- A new report on a flash flood that killed 20 people at a remote Arkansas campground last year says floodwaters reached an average depth of 7 feet in part of the campground and flowed at up to 7.5 mph.

Robert Holmes, a national flood specialist who was a co-author of the U.S Geological Survey report, says you couldn't stand up in it.

Seven children and 13 adults from Arkansas, Louisiana and Texas died in the flooding at the Albert Pike Recreation Area, which came when a storm system dumped a tremendous amount of rain on the valley.

The Geological Survey sent scientists to study what happened. They used high-water markings and the contours of the land to determine depths and speeds of the flood at the campground in southwest Arkansas.