A Toronto teacher has been charged in connection with the death of a 15-year-old student who drowned on a school field trip to Algonquin Park last year.

Jeremiah Perry, a student at C.W. Jefferys Collegiate Institute, was swimming with classmates in Big Trout Lake on July 4, 2017 when he disappeared under the water.

His body was found by search and rescue divers one day later.

In the days following his death, the Toronto District School Board (TDSB) said Perry was among 15 of the 32 students on the trip had not passed the required swim test.

Perry, specifically, was also not recorded as having participated in mandatory swimming lessons held by the school before the trip. He was not wearing a life jacket when he went into the water that day.

On Thursday, just over a year since his death, Ontario Provincial Police announced charges in the case.

Following a “thorough and professional investigation,” OPP charged Nicholas Mills, of Caledon, with criminal negligence causing death.

Mills is a teacher at C.W. Jefferys Collegiate Institute, police said, and the coordinator of the school's REACH Program.

The TDSB confirmed that Mills remains on home assignment, where he has been since Perry’s death.

“He was supervising and a designated team leader for Jeremiah Perry’s group,” Const. Catherine Yarmel told CP24 via phone. “He was officially responsible for the Algonquin itinerary and overall supervision.”

Police said they conducted more than 100 interviews, executed one search warrant and four production orders as part of their investigation.

Perry’s father, Joshua Anderson, said he still relives the phone call from a TDSB official, calling it “every parent’s worst nightmare.”

“Since that moment my family and I have been living in a constant state of shock and sadness,” Anderson wrote in a statement provided by his lawyer.

“This last year has felt like an eternity for my family and I, but we understand that it takes time to fully investigate a tragedy like this.”

Anderson said the family has been in regular contact with Ontario Provincial Police throughout their investigation.

He said they’re “relieved” by the decision to lay charges against the teacher.

“We believe these charges are warranted under the circumstances,” Anderson wrote.

“Although nothing that happens now can bring back Jeremiah or take away the pain of losing him, we hope that having the case proceed through the criminal justice system will be one important step in ensuring that a tragedy like this never happens again on a school trip.”

When asked about the charges Thursday, Toronto Mayor John Tory refused to comment, noting that the case is before the courts.

“I can tell you that I went to the funeral for that boy and I met his family and I stood next to his casket. Quite frankly, it was just one of those things where you said to yourself that this kind of thing shouldn’t happen,” he said at an unrelated news conference on Thursday.

“It is not up to me to assess or decide on blame for that. The courts and other places will do that but I will just say that I think when it comes to whether it’s field trips to Algonquin Park or whether it’s day-to-day traffic circumstances that we all collectively as a community have an obligation to keep kids safe.”

Perry’s death spurred the TDSB to conduct a review of its own. The board later implemented a number of new measures surrounding field trips, including that a principal review students’ swim tests results and that parents be notified if their child passed or failed.

In a statement, the board said it remains “deeply troubled” by the findings released in last year’s review. They vowed to continue to support the Perry family “in any way” while the case goes before the courts.

“Critical safety requirements, such as passing a swim test, do not appear to have been followed by the lead teach supervising this trip,” the statement reads. “Despite this, we have already strengthened our checks and balances to ensure something similar can never happen again.”

The TDSB said they continue to be cooperative with police.

Spokesperson Ryan Bird said the results of the TDSB’s investigation were only preliminary as OPP had directed them to suspend their internal probe once they launched a criminal one.

“Now that OPP has laid this charge, our own internal investigation can continue,” he said.

Bird said Mills was the “lead teacher” assigned to the trip and was responsible for ensuring safety requirements were followed.

No other trips were cancelled or paused as a result of the incident, Bird said, as the board felt the existing procedures were “sufficient.”

“Had they been followed, a number of people that did go on this trip would not of gone,” he said. “A number of them did not pass a swim test, which should’ve made them ineligible to go on the trip in the first place.”

In May 2018, a third-party review commissioned by the province also made a number of recommendations. The report, conducted by Deloitte, found that inconsistent degrees of alignment with Ontario’s physical education safety guidelines across school boards.

It recommended individual boards provide “clear parameters for the consistent monitoring of requirements for outdoor education and excursion by schools” and that the process be organized by “board-wide standardized tools and templates.”

Mills is due to appear in court on the charges on September 11.

With files from the Canadian Press