An 18-year-old woman rescued younger relatives from treacherous river waters below a dam in northwestern Minnesota only to lose her own life after being pulled under, authorities in Clearwater County said Tuesday.

The heroics of Raina Lynn Neeland, of nearby rural Bagley, occurred Monday afternoon at the Clearwater Dam in Sinclair Township, where water from Clearwater Lake flows over the 14-foot-high dam into a river with the same name, according to the Sheriff's Office.

That's where Neeland and seven children — both siblings and cousins — were going over the off-limits dam and into the river but got caught up in the turbulent water and could not free themselves, the Sheriff's Office said.

"They use it as a big waterslide," Sheriff Darin Halverson said Tuesday. "Kids like to do that. ... They use tubes or whatever. Lots of times they go over on their own."

Neeland had pulled some of the youngsters, the youngest 6 years old, to safety before she went under the water.

"We probably would have had multiple fatalities," said Halverson. "The water is just churning under the dam. ... She did her part and saved who she could."

Bystanders freed an unresponsive 8-year-old girl from the water, and one of them resuscitated her.

Meanwhile, other bystanders performed cardiopulmonary resuscitation on Neeland, who also was unresponsive. Witnesses estimated that she had been in the water for roughly 10 minutes.

An air ambulance arrived at the scene, about 30 miles northwest of Bemidji, but medics were unable to revive the young woman.

Others on the scene joined the young woman in sparing others a deadly fate, said Jeremy Neeland, an uncle to Raina.

"We could have been burying five of them out of the eight," he said.

The uncle described a "mystery woman" who brought 8-year-old Jada Neeland back to life. "I would like to thank her," he said.

Raina's teenage brother Blaze grabbed a "kind of unconscious" 15-year-old cousin by the ankle and "had enough power to pull" the 240-pound relative from the roiling waters, Jeremy Neeland said.

The water level at the dam, which is owned by the Minnesota Department of Natural Resources (DNR), was considerably higher due to the large amount of rain recently.

The uncle said the children had been swimming at the dam at least three other times this summer, but "8 inches of rain turned the river into a rapids. ... They didn't realize where the undertow was, and them little kids went under."

Even when less perilous, Sheriff Halverson said, the waters on both side of the dam are not to be used for fishing, swimming or thrill-seeking. There are signs clearly posted warning people to stay away, he said.

"When the water level is lower, it's not as dangerous," said the sheriff, who has lived in the area for all of his 48 years. "But it's always dangerous when you are dealing with a dam."

Brooke Pond, who grew up in Bagley and is now the clerk for Sinclair Township, said, "We used to swim there as a kid. It's a pretty common local hangout. Now as a mom looking back on it, that probably wasn't such a good idea."

Pond said that when not being fed by heavy rainfall, the river's surface at the foot of the dam "looks nice and calm. But we got a bunch of rain, so the water there is really high."

A township meeting was scheduled for Tuesday night, and Pond said she intended to bring up Neeland's death and push for barriers to be installed.

"The young lady who lost her life, she died a hero," Pond said. "It's a sad thing. Would have been better if it didn't happen at all."

The sheriff couldn't recall any other deaths associated with the dam, which was built in 1931, but "we've had some close calls."

Halverson said he's brought up with local officials that chain link fences need to be installed to "keep people out of there. But I don't even know if that's possible."

Jason Boyle, the DNR's state dam safety engineer, doubts anything can keep people from accessing the dam, which is among about 80 others in Minnesota that were classified in 2005 as "drowning machines" because of the strong undertow the water creates.

"Physical barriers? People find a way around them," Boyle said. "It's really impossible to keep people from finding a way to get in."

Since 2005, the DNR has minimized the potential danger of roughly half of these dams by adding rock at the bottom to weaken the current's flow.

However, Boyle added, that strategy would not likely work at the Clearwater Dam, because "you can't make that opening so small that you can't let a flood get through. ... It could cause the water to go over the top of the road" that runs atop the dam.

Lacking any solution anytime soon, the sheriff wants people to stay away, and that includes his own two children.

"Every once in a while, they bring up that their friends are going," Halverson said, "and I tell them don't go."