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Is There a Duty to Warn of Obvious Dangers?

By Jocelyn-Rose Brogan

There are dangers in everyday life, but people do not need to be warned of all dangers.  For instance, people do not need to be warned that jaywalking in rush hour traffic is dangerous.

In occupiers’ liability claims, defendants should consider whether an alleged danger is an obvious one, in which case it should be argued that no warning about the danger was required.

To determine what qualifies as an obvious danger, a common theme is the use of a common sense approach. For example, what would be the purpose of a warning sign or instruction that would only tell an individual what they already knew from their own observations?

In this article, cases are outlined which address whether there was a duty to warn of dangers in four particular settings: a grocery store, a fitness centre, a park, and a recreational trail.

Grocery Store

In Miltenberg v. Metro Inc., 2012 ONSC 1063 (“Miltenberg”), the plaintiff, an elderly lady, alleged that she was injured while attempting to remove the bottom of two cream containers stacked one on top of the other from the top shelf of a freezer at the defendant’s grocery store.

One of the arguments advanced by the plaintiffs was that there ought to have been signs cautioning customers that items may fall from their placement on higher shelves. 

The motion judge rejected the plaintiffs’ argument that the defendant had a duty to warn customers that reaching for goods on the top shelf could cause injury. He considered the risk to be obvious, stating:

…customers do not need to be warned that ice cream containers or any item could fall on them if not gripped properly. I accept that individuals are fully capable of figuring out whether they can reach items above head height and whether they can do so in a safe manner…I am not satisfied that a store must have warning signs scattered throughout the store to denote the potential danger to customers if one decided to secure an item from a shelf above one’s height.

The motion judge employed a common sense approach and dismissed the plaintiff’s action on a summary judgment motion.

Fitness Centre

In Hosseinkhani v. QK Fitness Inc., 2019 ONSC 70, the plaintiff alleged that she was injured during a fitness class when she tripped over a circular dumbbell which had rolled from the original position and into her path of travel.

The fitness instructor directed the class members where to position the dumbbells, but no instruction was provided on how the circular dumbbells should be placed to prevent them from rolling.

One of the arguments advanced by the plaintiff was that QK Fitness had a duty to properly instruct her on the safe use of the round dumbbells, which they failed to do.

In response, QK Fitness argued that the plaintiff made the simple mistake of placing the round dumbbells on their side rather than on their flat end, and that it should be obvious that a round object might roll if placed on its side.

The defendant was successful on its summary judgment motion. The Court of Appeal upheld the motion judge’s dismissal of the action in Hosseinkhani v. QK Fitness Inc., 2019 ONCA 718.

The motion judge found that there was no evidence that the round dumbbell posed an unusual hazard, and that neither the dumbbells, nor the exercises themselves, were inherently hazardous. The motion judge also found that a round dumbbell rolling is an obvious risk. No warning was required.


In Winters v. Haldimand (County), 2015 ONCA 98, a 16 year old boy fell from a tree at a park and was rendered a paraplegic. 

The evidence disclosed that generations of teenagers had climbed up the tree and used it as a place to gather. The tree was known by some teenagers as “The Chilling Tree”. However, no municipal witness had ever seen anyone climbing into the “Chilling Tree” before the subject incident, nor had their been any complaints about the tree.

The trial judge found that the County’s monitoring of the tree’s usage was reasonable in the circumstances. While the County did not know about the tree’s usage, they did not fail in any duty to ascertain that usage.

The trial judge also found that there was no evidence which suggested that there was anything inherently dangerous about the “Chilling Tree” beyond the trunk or limb in question. He stated: “[t]rees, by their very nature, things which can be climbed, and therefore fallen from, are potentially harmful”.

The Court of Appeal, in upholding the dismissal of the action, stated:

any danger posed by this tree was an obvious one.  If you chose to climb it you could fall and be injured. There is no duty to warn of such an obvious and self-evident danger nor any duty to monitor beyond what the Township is doing at the time of this most unfortunate accident.

Therefore, no warning of the danger of climbing the tree was required since the risk was obvious.

Recreational Trail

In Karpouzis v. Toronto (City of), 2020 ONSC 143, the plaintiff suffered a serious brain injury while skateboarding at nighttime on a recreational trail. He sued the City of Toronto (the “City”) for negligence. 

Pursuant to section 4(3) of the Occupiers’ Liability Act (“OLA”), the plaintiff had willingly assumed the risk associated with skateboarding on a paved recreational trail at night. Therefore, a lower standard of care for an occupier applied pursuant to section 4(1) of the OLA. The City owed a duty to not create a danger with the deliberate intent of doing harm or damage and to not act with reckless disregard. 

The plaintiff argued that the City showed reckless disregard in its failure to post signs warning of the hazards of nighttime use on the trail because of inadequate lighting or rapid changes in illumination.

The motion judge disagreed, stating:  “…it was not necessary to post signs to warn that at nighttime, an obviously unilluminated path leading into a wooded area would have slow to rapid changes in illumination and inadequate lighting for a pedestrian, cyclist, rollerblader, or skateboarder travelling without a flashlight”.

The motion judge granted summary judgment to the City and dismissed the plaintiff’s claim.


There is risk involved in everyday interactions between individuals and society. While it may be beneficial for occupiers to err on the side of caution when assessing risk and implementing procedures, common sense often dictates what is reasonable in the circumstances.

The law does not require occupiers to warn of obvious dangers. Were that not the case, we would live in a society with warning signs virtually everywhere and with occupiers constantly telling people to “watch out” for every little thing. That would dilute the effect of truly necessary warnings.

As stated in Miltenberg: “[j]ust because a matter becomes litigious and the parties seek redress through the courts, does not mean that any concept of common sense evaporates”.