A 6-year-old boy survived a plunge into the Big Sioux River Thursday evening, but two people who jumped in to help the boy are believed dead.
NBC affiliate KDLT reports that the stretch of the river was covered with 6-10 feet of icy foam produced by upstream rapids.
"A relative of his jumped in after him and then a male jumped in after them. So, we had three people in the water," Sioux Falls Fire Rescue Chief Jim Sideras told KDLT.
The boy was able to climb out of the river shortly after the two rescuers jumped in around 6 p.m. Thursday.
A friend of the missing man told the TV station, "By the time I got there he was already in there and they had [the boy] by the arm. They had the kid in his arm and he slipped and he fell. And then not too long after that the kid popped up a little bit to the right and climbed up the rocks by himself."
ABC affiliate KSFY reported Friday morning that the missing woman is 16-year-old Madison Wallace, the boy's sister. The missing man, identified only as a bystander, is 28-year-old Lyle Eagletail.
The rescue operation ended at 2 a.m. Friday, indicating that finding Wallace and Eagletail alive is considered unlikely. Sideras hailed their actions as "brave and noble," but told KSFY that in the future observers should "stay on the shore" and "make continued contact" with the person in the water.