Rescue crews spent nearly six hours searching for a missing swimmer Saturday afternoon in Lake Michigan near Highland Park, Illinois.

Around noon, Highland Park police and firefighters responded to a call of a swimmer struggling in the lake near the Openlands Lakeshore Forest Preserve near Fort Sheridan.

Another swimmer tried to help the person who had gone missing, but was unable to reach them.

Police and firefighters from Highland Park and several neighboring suburbs launched rescue boats and a drone to begin searching for the missing swimmer.

During the search, one rescue diver brifely went missing, but was found uninjured.

Peter Mordini, who was out on his boat at the time the swimmer went missing, said he missed the swimmer by five minutes, but he came across a woman also in distress who was trying to save him.

"It's hard to see. This poor guy was out there in distress, and we just couldn't get it," Mordini said. "There was three or four people he was waving to, and they were on the rocks, and she had the courage to go try."

He said, because of the lake's strong currents, that woman couldn't reach the man in distress.

"She was telling us, 'There's someone drowning here. You have to find them. …I went down for about a half hour underwater, trying to find him in about 15 feet of water, and we took her out because she was tired, and it was about a couple football fields out," he said. "The nice weather and the warm water brings people out like this, and you've got to respect that lake. These winds are blowing out. You don't realize it's easy to swim out, but to come back in is a different story."

Jessie Baker was also boating nearby.

"With the clouds and everything it wasn't too easy to see deep under the water," Baker said. "We were trolling around helping to look until the Coast Guard and everything got there."

The search was suspended at 6 p.m., and crews planned to return to the lake at 8 a.m. Sunday to resume the search.

The swimmer has not been identified.