Two swimmers were pulled from the waters of Lake Harriet at the lake’s North Beach on Wednesday evening and taken to Hennepin County Medical Center, police said.

The two females, ages 17 and 20, are in stable and serious- to-stable condition, respectively, said Hennepin County Sheriff’s Office spokeswoman Rebecca Gilbuena. The swimmers names were not released.

Just before 5 p.m., the swimmers went under the water while attempting to reach a floating swim dock, Gilbuena said. The teenager was able to surface from the water without help, but a witness located the 20-year-old under the water’s surface and pulled her ashore, where bystanders administered CPR.

It was unclear whether she was still breathing as rescuers provided aid, police said.

“I can’t repeat this water safety message enough: Watch, Wear, Learn,” Hennepin County Sheriff Rich Stanek said in a statement Wednesday. “Watch your kids. Wear your lifejacket. Learn to swim.”

Lake Harriet’s North Beach has lifeguards on duty during the season from 11 a.m. to 7 p.m. daily, but the Southeast beach does not employ lifeguards. The lifeguard season officially starts Saturday, according to the Minneapolis Park and Recreation Board website.