Flash floods are one of the most dangerous natural occurrences because they happen so fast.
A perfect storm of deadly conditions was the backdrop for the horrific flash floods that swept away an Arkansas campground late Thursday into Friday morning.
Sixteen of 18 bodies have been identified after the torrential floods hit the Albert Pike Recreation Area in Cappo Gap, Ark., Capt. Mike Fletcher of the Arkansas State Police said today during a press conference in Langley, Ark.
Two dozen people remain unaccounted for, he said, but "we're going to continue to cover [the 20-mile area] as long as it takes" to account for the missing.
Rain caused one river to rise from three-and-a-half feet at 1:30 a.m. to more than 23 feet in just four hours, an extremely dangerous rate.
Another key factor in the Arkansas flash flood was the geography of the campground. It is surrounded by mountains on either side, so as the rain hit the mountains, it quickly rushed into the valley below, acting as a funnel and pooling the water to one area.
That caused the Caddo and Little Missouri rivers to rise at a rate of 8 feet per hour at times.
Making matters worse was the sandy soil along the campground. Sand cannot absorb water.
Jan McRae, one of the owners of the Albert Pike campground, whose family has lived in this part of Arkansas for generations, told "Good Morning America" today she was in bed when she received a phone call from across the river about the flash flood. She could hear the sounds of the water roaring and trees breaking off.
"One of the first things I heard when we got down to the water, I heard a woman screaming for help, and it was so hard to tell where the call was coming from because the water was so loud," McRae said. "We did find her, and my husband and one of the state troopers and some of the other campers stayed there by the water with her and encouraged her to hold on until the water went down."
The camper was rescued as soon as rescuers could get to her, McRae said.
McRae also could hear the sounds of families -- parents separated from children and vice versa.
"That's the most heartbreaking part of it," she said.
"It's just, it's a miracle that some of them had to be rescued like that but ... we did account for every one of them before the day was over [Friday]," McRae said.
About 60 campers were rescued by emergency workers, another two dozen hospitalized, The Associated Press reported, citing authorities.
"About 1:30, 2 in the morning, we started hearing children and women screaming and crying," said Crystel Hofer, who was asleep in her cabin when the water came raging through. "So we went to the door and opened the door and they were trying to come up the hill to where our cabin was to escape the rising water."
"It's a terrible tragedy and we're doing all we can to hopefully find some folks and bring some people back who are stranded out there," said Matt DeCample, spokesman for Arkansas Gov. Mike Beebe. "We've got a lot of state and local folks pulling together. This is an unprecedented tragedy out in this part of the state. It's a very rural but close-knit portion of Arkansas."
The area was still heavily flooded Saturday as searches were ongoing.
The Caddo and Little Missouri rivers -- two normally gentle waterways -- rose by more than 20 feet overnight, engulfing the hikers and campers who were spending the night in tents along the rivers in the isolated Ouachita Mountains.
"Within 10 minutes, the water had rose and campers were floating down," Hofer told ABC News. "If they didn't get out of their camper within five, 10 minutes, they weren't getting out."
The 54-unit campground was quickly inundated with water. The water was so violent it overturned RVs and peeled asphalt off the roads.
"There was a lot of devastation in there, where it's coming along this river," said Capt. Mike Fletcher of the Arkansas State Police Department. "There's vehicles that's overturned, there's cabins washed off their foundations."
The area affected, the Albert Pike campground, is managed by the U.S. Forest Service and is about 75 miles west of Little Rock. It is a popular camping area, partly because of its secluded location. Officials say they expect more deaths but do not yet have a full count on the number of people at the site or missing.
"We don't know who was in there last night," State Police spokesman Bill Sadler told The Associated Press. "This is a very wide area."
Brigette Williams, spokeswoman for the American Red Cross in Little Rock, told The Associated Press that between 200 and 300 people were believed to be in the area at the time of the flooding. She did not know how many of those were campers and how many were local residents.
DeCample said people there would have had "very little warning or alerts" because the flooding occurred while most people were sleeping. And because the area is so remote and terrain so rugged, officials believe that campers would have had to hike downstream in the dark to escape the valley, making the chances of survival for some even slimmer.
The Little Missouri west of Caddo Gap stood at 3 feet Thursday, but after 7.6 inches of rain fell in the area overnight the level jumped to 23.5 feet by Friday morning. It later dropped to 11.5 feet.
Searchers were working along the Little Missouri River in Montgomery and Pike counties and the National Guard dispatched helicopters to help in the rescue.
"We're just in the process of right now, trying to see if we have anyone to be rescued along the river there, and uh, also in a recovery stage," said Capt. Fletcher.
Officials were also bringing in a refrigerated truck to serve as a temporary morgue and downstream Glenwood police and fire crews monitored river debris moving beneath a highway overpass.
Two Shreveport, La., families were at the Albert Pike campgrounds when the floods hit, a family friend told ABC affiliate KTBS.
A 5-year-old member of one family was swept away by flood waters, and the father and a 2-year-old child were missing, said Tonya Rabalais of Shreveport.
The father of the other family -- which consisted of a husband, wife and three children -- was missing, Rabalais said. The mother of the first family and four members of the second family survived.
The Associated Press contributed to this report.