Three Chicago high schoolers on a retreat to teach young black men to become "ethical leaders" drowned early Friday after they sneaked away from their camp in the middle of the night and launched paddle boats whose floor plugs had been removed for the winter.

The boats quickly sank in the Fox River, dumping the teens in the swift current of 42-degree water.

Chaperones at the leadership retreat were likely asleep when a group of students launched paddle boats into the river, said John Greene, battalion chief of the Algonquin-Lake in the Hills Fire Protection District. It was not clear how many teens ended up in the water.

"Shenanigans," Greene said. "That's what it looks like."

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A group of 31 boys — sophomores, juniors and seniors from North Lawndale College Prep — were at Camp Algonquin on a school trip organized in conjunction with the Georgia-based leadership group VisionQuest International, said Chicago Public Schools spokesman Mike Vaughn. They were on an eight-day retreat at the camp that was to end Friday.

"These are kids that have potential, potential to be leaders," Vaughn said.

Their school on Chicago's West Side serves an overwhelmingly black and poor student population. It's a charter school that aims to prepare students from communities with few resources to succeed in college.

The McHenry County coroner's office identified the students as 17-year-old Melvin Choice, Jr., 18-year-old Jimmie Avant and 16-year-old Adrian Jones. Authorities said the swift currents and debris made it difficult for them to remove the bodies from the river near the camp that's about 40 miles northwest of Chicago.

The swift-moving current also made the river unsafe for the students, said Lt. Julie Didier, a spokeswoman for the Algonquin-Lake in the Hills Fire Protection District.

"We definitely do not want to play games with the river," she said.

The school trip turned tragic when police responded about 2 a.m. to a 911 call that three teens were reported missing at the camp.

The drownings happened in a wooded area along the river where the trees have lost most of their leaves, revealing abandoned birds nests. At the water's edge, there are signs warning "Danger Riverfront Keep Out."

Didier said the students took six boats out on the water and they all sank. All boats had been recovered by Friday afternoon.

Authorities said after one boat quickly took on water, at least one student on shore went into the river to try to help, but ended up missing as well.

Didier said the three students' bodies were found about 50 feet from the water's bank in 8 to 10 feet of water.

"It was dark, it was rainy and icy," she said.

Robert Williams said his son was on the shore and unsuccessfully tried to swim toward the boys.

"He did all he could to try to save them, but he couldn't do it," Williams said.

The boats on the river were taken out of service for the season by having their bottom plugs removed, Didier said.

At the Chicago school, counselors were on hand to help students. The school remained open Friday although most students had gone home. Didier said two of the boys who died were seniors and one was a junior.

"It's a very sad, somber grief-stricken day," Vaughn said. "This is absolutely heartbreaking."

Student Kyra Brown, 14, paused to remember Choice.

"He read me a story that he wrote and got an 'A' on. It was beautiful," she said.

The surviving students who returned to Chicago from the camp were taken to a church not far from their school for a morning service.

The bus ride back was a somber one, said driver Willis Falls.

"They were very quiet, in fact, I didn't hear anybody say anything," he said.

The McHenry County Conservation District owns the 116-acre camp on the Fox River and the YMCA of McHenry County leases and operates it.

Linda Fauser, who runs the camp, said the groups that come to the camp are required to provide their own supervision.

She said the chaperones and students were all in one building together. She said the school group had four supervisors with them, well within the camp's required 8-to-1 ratio of supervisors per students.

However, Vaughn said there were actually nine chaperones on the trip — four people from the school, one administrator and four from VisionQuest. The company did not immediately return a call for comment.

Vaughn did not know details of what happened at the camp. He said the school district would investigate how the trip was organized and chaperoned.

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