MINNEAPOLIS (WCCO)Just one day after opening its gates, an innovative new pool in north Minneapolis had a drowning scare.

The Webber Park pool in North Minneapolis just opened on Friday. Around 5:00 p.m. Saturday, police got a call that a child had gone under the water and didn’t come back up.

READ MORE: Spartans Beat Gophers 75-67 In Big 10 Opener

After a frantic two-hour search, rescue crews called it a false alarm.

Authorities say a lifeguard thought a child jumped into the pool and never come back up. That’s when they evacuated the pool and Hennepin County Water Rescue crews took over.

Webber pool is the only natural public pool in North America, meaning it uses plants in a nearby pond to filter the water instead of chemicals — a new challenge.

READ MORE: Jazz Shoot Past Wolves 136-104 For 5th Straight Win

“This actually functions more like a natural lake, so water clarity was definitely an issue here,” Hennepin County Sheriff Lieutenant Steve Tait said.

After a couple of hours it was clear the possible drowning was a flase alarm… the best news for those who had just come for a nice swim on a hot day. Authorities warned that lifeguards shouldn’t be the only ones looking out.

“We need parents and guardians to stay in touch with their kids,” Nicholas Williams of the Minneapolis Parks Board said. “You can’t bring your kids to pool and leave creates emergency situaiton for everybody.”

MORE NEWS: Hennepin Co. Sheriff Dave Hutchinson Investigated For Possible DWI

Park authorities say the new pool drew in so many people that some had to be turned away. They said there were 12 lifeguards present, which complies with state and county rules, but they’re going to look into possibilty adding more when it’s so crowded.