LITTLE ROCK (AP) — A lawsuit filed by family members of three of the 20 people killed in a violent flash flood in a federally operated campground in southwest Arkansas last year claims the government was negligent by leaving the people there in danger.

The federal lawsuit was filed on behalf of the survivors of Kay Roeder, 69, Deborah Roeder, 52, and Bruce Roeder, 51, all of Luling, La. The flood also killed people from Arkansas and Texas.

A violent storm dropped heavy rain on the Ouachita Mountains in the early morning of July, 11, 2010, and the water drained into the Little Missouri River, along which 200 or more people were staying in the Albert Pike Recreation Area Campground.

A torrent as high as 23 feet yanked trees out of the ground, toppled vehicles, lifted large asphalt slabs and stranded survivors for hours.

Seven children were among the dead.

The extended Roeder family was on vacation, with some members sleeping in tents and four family members, including the three who were killed, sleeping in an RV, according to the lawsuit.

Tara Roeder, daughter of Bruce and Deborah Roeder, was in the RV, along with Kay Roeder.

The lawsuit says the RV started rocking at about 3 a.m. and everyone inside woke up. Then something large hit the side of the RV, knocking it over and causing it to roll over and float.

"There was another powerful impact, and the camper imploded," the lawsuit states, dumping the family into the floodwaters, which rose at a rate of 8 feet per hour.

Tara Roeder was able to cling to a tree by wrapping her arms and legs around it, and had to do so for more than two hours until the waters receded enough for her to wade to dry ground and wait with others for rescue.

Theresa Roeder, daughter of Kay Roeder, is the other lead plaintiff in the suit.

The Little Rock law firm of Wilkes & McHugh issued a news release Thursday, saying the campground never should have been built because of its location in a flood plain. The wrongful death suit was filed Aug. 4 in the Western District of Arkansas. It seeks damages for the deaths and for the mental anguish of the survivors. It doesn’t list a dollar amount.

A Forest Service spokesman didn’t immediately return a phone message seeking comment.

The Forest Service in October released a report that acknowledged there was no emergency warning system in the campground. The National Weather Service office in North Little Rock twice phoned local authorities warning of the extreme flood danger but the warning was never transmitted to the people sleeping in the campground.

The lawsuit says the government failed to evacuate the campers or to even post signs warning of flood danger, as the narrow gorge where the campground was located has historically been prone to flooding. Many homes in the adjacent area are built on pilings.

Also, the lawsuit states that the Forest Service failed to fix a radio repeater that had been broken for six months and would have allowed two-way radio communication into the gorge. During the days-long search for bodies through dense woods and high debris piles, a mobile cellphone tower had to be brought in so officials and others could communicate.

The suit further accuses the Forest Service of "fraudulently misleading engineers and architects" hired to build the campground by failing to notify them of the flood danger in the area.

Death certificates attached to the lawsuit show drowning as the cause of death for each of the Roeders.