In Deborah Tilli v. Hamilton-Wentworth Catholic District School Board et al., 2019 ONSC 1783, released on May 31, 2019, the Ontario Superior Court of Justice dismissed a claim that a school board was negligent and did not adequately supervise two students during a physical fight at school.

Ms. Tilli and Ms. DiTomaso were 15 years old and attending grade 10 at St. Jean de Brébeuf High School in the Hamilton-Wentworth Catholic District School Board (School Board).

On September 19, 2008, Ms. Tilli and Ms. DiTomaso were involved in a physical altercation which caused injuries to Ms. Tilli. The altercation took place during a three-minute transition period between first and second periods in a busy hallway at school.

There were conflicting versions of what occurred and who initiated the fight. Ms. Tilli claimed the fight was initiated by Ms. DiTomaso, and vice versa. The altercation ended when Ms. DiTomaso banged Ms. Tilli’s head on the floor more than once.

Ms. Tilli filed a personal injury claim against Ms. DiTomaso and a claim against the School Board and teachers stating that they were negligent for failing to provide adequate supervision and prevent the incident from occurring.

Court finds Student partially liable for damage caused during fight

After considering the varying versions of the story told by the parties and witnesses, the court concluded that Ms. DiTomaso was liable for the injuries she inflicted on Ms. Tilli, however, who started the fight was not an important issue since this was a “consent fight” and they were both willing participants.

The court determined that the incident was likely triggered by Ms. DiTomaso calling Ms. Tilli offensive names at the time of the incident and on prior occasions. It began as a shouting match, and was likely followed by kicking and slapping, mutual hair pulling, pushing and shoving. Both girls lost their balance and fell to the floor, with Ms. DiTomaso ending up on top of Ms. Tilli.

The court decided that the fight stopped being consensual when Ms. DiTomaso grabbed Ms. Tilli’s hair on each side of her head and banged the back of her head forcefully on the tile floor more than once.

Moreover, the court stated that provocation is a form of contributory negligence and mitigates damages. Ms. Tilli would have known that calling Ms. DiTomaso names in front of other students would eventually provoke a reaction, which it did. Therefore, the court found Ms. DiTomaso to be responsible for 60 per cent of the damages.

Court dismisses claim against School Board and teachers

The court assessed whether the School Board or the teachers were liable based on the standard of care set out by the Supreme Court of Canada in Myers v. Peel County Board of Education, [1981] 2 S.C.R.. The standard of care expected of educators is that of a prudent and careful parent.

The supervision schedule that the school had in place at the time was to supervise high traffic areas when students were in class, such as the front door area and the cafeteria. Since there were only three minutes between periods and the hallways were full of teachers going from one class to the next, there was no formal supervision schedule for the hallways during transition periods.

The court described the incident as follows, at paragraph 95:

“It is not lost on this court that this was a sudden and spontaneous event that escalated and finished in approximately 30-45 seconds. Only by having a teacher posted in the exact area of this incident, at the very time it occurred, could the school perhaps have prevented the fight from occurring. Such a standard is not reasonable and certainly not one any reasonable and prudent parent would be expected to adhere to with its own teenage child.”

Moreover, because the noise level was so high during the transition period, it would be very difficult for teachers to distinguish the noise of a fight from the usual noise of chatter and laughter until attention was drawn to it.

The court paid particular attention to the context, namely that the incident involved two fifteen-year-old students without a history of violence or discipline, noting the following at paragraph 92:

“In this case the standard is that of a parent of 15-year-old teenagers, none of whom had any predisposition to violence or animosity with each other. Neither party had any type of discipline issues. As well these teenagers were well aware of the zero tolerance policy of the school for any type of fighting or violence and were obviously aware that serious repercussions would be enacted for any breach of that policy.”

The court further noted that fifteen-year-old students are not constantly supervised by a careful parent. It stated at paragraph 94:

“A 15-year-old teenager is not supervised constantly by a careful parent. They go out alone with friends, they travel to school alone, they are no doubt at home alone for periods of time, they take public transportation alone and many babysit younger children or have other part time work. In short, they are young adults who are aware of what is expected by way of behavior in a civilized society, without being supervised constantly.”

The school had a supervision policy in place. There were surveillance cameras and numerous teachers circulating in the hallways for three minutes between classes. There was no evidence led by the plaintiff as to what else the school should have done to prevent this incident from occurring. No expert evidence showed that the school’s supervision on the occasion in question fell below the standard of a reasonable and prudent parent of a teenager.

Since the actions of the School Board and its teachers did not fall below the accepted standard of care, the court dismissed the claim against them.


This recent application of the principles in Myers reminds educators of the importance of having adequate supervision and policies for expected student behaviour. Further, it highlights that the standard of care of a reasonable and prudent parent be appropriate for the age and characteristics of the student and the setting. The adequate supervision of average teenage students does not necessarily require constant supervision.