An Ontario teacher has been charged in the death of a 15-year-old student who drowned last year on a canoe trip organized by his Toronto school, police said Thursday.

Provincial police spokeswoman Const. Catherine Yarmel said the man was responsible for co-ordinating the trip to Algonquin Park where Jeremiah Perry died.

Nicholas Mills of Caledon who taught at the high school Perry attended, was charged Wednesday with criminal negligence causing death, Yarmel said.

The charge comes about a year after police began a criminal probe into Perry's death.

"The OPP conducted a thorough and professional investigation, which included over 100 interviews, along with the execution of one search warrant and four production orders," Yarmel said.

Perry was on a school trip with other students from C.W. Jefferys Collegiate Institute last July when he went for an evening swim and disappeared underwater. His body was found the OPP's underwater rescue unit the next day.

The Toronto District School Board said weeks later that Perry was among 15 of 32 students on the trip who had not passed a mandatory swim test, and apologized to the teen's family.

John Malloy, the board's director of education, said an initial swim test took place in a lake, and that students who did not pass the first test should have been required to take a second test at school. But, he said, the second test was neither provided nor offered.

The board has since implemented new procedures that include school principals having to see a list of students who pass or fail a swim test before a trip, and parents having to be notified of the results.

The board did not immediately comment on the charge against Mills.

The province launched a review of outdoor education policies after Perry's death, which recommended boards develop guidelines for monitoring compliance with safety procedures and create a support centre that would give staff standardized access to information on safety guidelines and other resources.

Toronto Mayor John Tory said Thursday that communities "have an obligation to keep kids safe."

"I went to the funeral for that boy and I met his family and I stood next to his casket quite frankly and it was just one of those things where you said to yourself that kind of thing shouldn't happen," Tory said.

Mills is scheduled to make his first court appearance in Toronto on Sept. 11.