Authorities searched in vain Sunday for two people — one a teenage boy — who went missing in fast-moving rivers on a busy holiday weekend.

Twelve divers worked in shifts trying to find a 14-year-old boy who disappeared in the Mississippi River on Sunday afternoon while with two friends at Lions Levee Park in St. Paul Park.

About three hours later, the search shifted into recovery mode. "The rescue effort has been exhausted," said Sgt. Tim Tuthill of the Washington County Sheriff's Office.

On the St. Croix River, Chisago County authorities were looking for someone missing near Taylors Falls. The searches came on a warm Memorial Day weekend amid warnings about high water in waterways across the metro area.

As of late Sunday, authorities had not identified the 14-year-old presumed drowned in the Mississippi River.

A friend, Heather Cramer, 13, was one of two people with him, her father, Philip Cramer, said. He said the boy was in the water, "pretending that he was drowning," and at one point, didn't resurface. Heather waited to make certain he wasn't "playing," and then "she went in there to try to look for him," Philip Cramer said.

Authorities were called to the scene at 5:13 p.m. Much of the search took place west of an island in Lions Levee Park.

A boat with sonar equipment remained in the river after nightfall.

James Walsh and Anthony Lonetree