May 26, 2012 -- Chicago's beaches officially opened Friday, a sunny and warm day that again made clear why Lake Michigan is so inviting in the summertime.

But Friday also brought a reminder of the lake's potential dangers. Not long after lifeguards took their post for the first time this season, divers found a body while searching for 15-year-old Lexie Adu, who had been swept into the lake Thursday at Loyola Park Beach on the Far North Side.

Frank Adu, who was at the beach for much of the search, said his daughter Lexie was an honors student at St. Scholastica Academy in Chicago who had gone to the beach with two classmates. The body was found near a metal barrier that juts about 50 yards into the lake.

"She was just enjoying the weather," Adu said. "And I think the waves just carried her away."

Authorities were alerted that the girls were struggling in the lake at about 6 p.m. Thursday. Lexie's friends made it ashore, and crews from the Coast Guard and police and fire departments searched for Lexie in 60-degree water whipped by high winds until about 2 a.m. Friday.

Within a few minutes of restarting the search about 8 a.m., divers found a body in 15 feet of water, said Deputy District Chief Ron Dorneker, head of the _Chicago Fire Department_ dive team.

Fire officials Friday would not confirm the age or gender of the body, or that it was Lexie. But after police and fire officers spoke to Adu, he let out a wail and collapsed onto his hands and knees.

Friends helped him to his feet, and he took several steps onto the sand before his legs buckled again. He was taken to a nearby ambulance and left about 30 minutes later in a cab filled with relatives.

A veteran Park District employee said drownings at Lake Michigan beaches when lifeguards are on patrol are rare. According to the Great Lakes Surf Rescue Project, which tracks drownings in the Great Lakes, 10 people drowned in Lake Michigan in the Chicago area in 2011 through mid-September. The group counts eight drownings in the lake off Chicago and the suburbs so far this year.

Last year, a North Shore official called the lake an "attractive nuisance" after the drowning of a 14-year-old boy in an area where swimming was prohibited.

On Friday, Adu smiled as he talked about his daughter, the second-oldest of his four children and a straight-A student who dreamed of becoming a doctor because of her own childhood bout with illness.

As a young girl, Lexie needed surgery to remove a cyst on her spine. She spent four days at _John H. Stroger Jr. Hospital_ (http://www.chicagotribune.com/topic/health/hospitals-clinics/john-h.-stroger-jr.-hospital-of-cook-coun ty-ORGHC00039.topic) and was impressed by the doctors and nurses who cared for her, Adu said.

"They took such good care of her," he said. "She thinks she owes everyone her life, she owed it to the whole world to become a doctor.

"That was not to be, I guess."

Lexie was born in the United States, but the family moved to her father's native _Ghana_ (http://www.chicagotribune.com/topic/intl/ghana-PLGEO00000111.topic) in 2007. Two years ago, Lexie begged her father to move back to the United States, where she thought she'd have a better chance to pursue a career in medicine.

"She said, 'I have seen how people (in Ghana) struggle, and I will not forget them,'" her father said.

At St. Scholastica, Lexie was also a track athlete and popular member of a close-knit freshman class of 50 girls, said President Loretta Namovic. Classes Friday were followed by an all-school liturgy to offer prayers for Lexie and her family, and grief counselors were at the school, which will close for good when classes end next week, Namovic said.

"Everyone here is in shock and trying to come to terms," she said.

Lifeguards patrolling Loyola Park Beach on Friday said the barrier that extends into the lake is off-limits, and visitors confirmed that lifeguards regularly shoo people away from the structure. Two lifeguards were stationed within 100 yards of either side of the barrier, scanning the water as swimmers splashed in the shallow water near the shore.

News of the drowning gave pause to beachgoers enjoying Friday's warm temperatures.

"It makes you think twice about bringing your kids (to the beach)," said Raquel Martinez, 26, who went to the beach as often as twice a week with her 4-year-old son last summer.

"He wants to go in the water today, but I won't let him. I had to explain to him (about the drowning)," Martinez said. "That's why I don't want him to go in."

Adu said Lexie told him she was going to the park and spending time with classmates. When Adu last spoke to his daughter, about 3 p.m. Thursday, she asked him if he had dropped off her application at Gordon Tech High School, which she hoped to attend in the fall.

The teen had left her camera phone in her shoes, and in pictures taken that afternoon, she looked happy.