Their relatives, who couldn't swim either, looked on helplessly as six struggling teens screamed for help, then vanished and drowned.
DeKendrix Warner, the 15-year-old who was the first to fall in, was rescued by a bystander.
"I stepped and I started drowning," he said from his impoverished, inner-city Shreveport home in a low voice, his eyes staring at the ground.
The large group of family and friends had gathered for an afternoon of swimming and barbecuing in the oppressive heat. The group had only been at the river for about 10 minutes when tragedy struck - they didn't even have time to set up the barbecue.
DeKendrix said he was kicking and felt like the river was pulling him under. When he was finally pulled from the water, he told the man to go help his cousin.
Those who drowned were identified as the Warners: 13-year-old Takeitha and her older brothers, 14-year-old JaMarcus and 17-year-old JaTavious. The others were the Stewarts: 18-year-old Litrelle, 17-year-old LaDairus and 15-year-old Latevin.
The area where the drowning occurred is not a designated recreational or swimming area but is often frequented by swimmers and boaters. There are no lifeguards on duty.
"The river is a dangerous place. It's no place to even put your foot in if you don't know how to swim," said Shreveport Fire Chief Brian Crawford.
Swimming skills can be scarce among African-Americans like the teens in this tragedy. A study commissioned by the sports governing body USA Swimming found 69 percent of black children had low or no swimming ability compared to 41.8 percent of white children. Segregation kept blacks out of public and private pools for decades and the disparity continues because many poor and working class children have limited access to pools or instruction.
The study didn't look into swimming ability based on rural versus urban environments.
The drowning "confirms that what we are finding, that this continuing cycle of people not knowing how to swim and their children not knowing how to swim and still being around water," said Sue Anderson, USA Swimming's Director of Programs and Services. "It's the continuing lack of awareness of how important it is that children learn how to swim."
The federal government says African-Americans drown at a rate 20 percent higher than whites. A lack of access to swimming pools and a lower interest in swimming skills are among the possible explanations, the Centers for Disease Control and Prevention said.
Marilyn Robinson, a friend of the families, told The Times of Shreveport she watched helplessly as the victims went under. She said a large group of family and friends, including roughly 20 children, were out at a sandbar to barbecue and have a good time. They frequent the area and were familiar with the water, Robinson said. DeKendrix said he had been going down to the river all week.
"None of us could swim," Robinson said. "They were yelling 'help me, help me. Somebody please help me.' It was nothing I could do but watch them drown one by one."
It took more than three hours to find all the bodies.
Associated Press writer Lisa Orkin Emmanuel in Miami contributed to this report.