I looked away for just a second. But here’s what I saw.

I was standing at the street corner waiting for my light to change. While waiting, a cyclist zipped by from my right to my left. The light changed and so I started to walk across the street. A few steps in, I heard a crash. Across the intersection to my left, I saw the cyclist sprawled out on the pavement. The bicycle was flung aside and its tires were spinning in the air. Just behind the bicycle was the telltale sign of what happened: a parked car with its driver door open. And in the span of a second, Vancouver claimed another “dooring” victim.

Cycling is as popular as ever. Have a look outside and you’ll see cyclists commuting to work, training for the next bike race, or delivering Foodora orders. These cyclists must share the road with drivers. Sometimes this can have disastrous consequences. Sometimes these disasters come from the mere act of exiting a parked car.

Opening a car door into the path of an approaching cyclist—dooring—can cause serious injury or death. Cyclists may suffer head injuries or break bones on their fall. Or they may lose control and fall into the path of other vehicles.

According to the City of Vancouver website, doorings were the most reported type of cycling collision. In fact, the city takes statistics on these incidents to identify danger zones. Main Street, Commercial Drive, and Broadway seem to stand out. Of course, those streets see a high volume of traffic. Even in smaller streets, cyclists aren’t immune from doorings. They are vulnerable because drivers on quieter streets may not think to look back when opening their doors.

How does the law apply to doorings? Are cyclists to blame for riding too close to parked vehicles? Or are drivers reckless for swinging their doors into the path of oncoming cyclists?

There is a specific law in B.C. that helps prevent doorings. Under the Motor Vehicle Act, a person must not open a car door unless it is reasonably safe. You have a legal requirement to see if it’s safe before opening a door on the traffic side of your car. And this applies to anyone—drivers and passengers alike. Failing to do so is an offence under the act, like running a red light. It can result in a fine.

Violating the Motor Vehicle Act isn’t the only legal consequence to dooring a cyclist. Dooring can also amount to negligence in a civil lawsuit. Doorings can form the basis of a personal-injury lawsuit. These cases are not uncommon, because of the seriousness of injuries caused by these incidents.

Physical contact between a car door and a cyclist is not necessary for a finding of negligence. Let’s say there is a near miss: a cyclist swerves out of the way of an opening door but gets struck by another car. It’s possible that the opening of the car door was negligent. The accident may be seen as completely or partially the fault of the door opener. That’s because opening the door was reckless and started a chain of events that led to injuries.

Any determination of fault will depend on the facts of any given situation. Fault may be shared by or apportioned to the cyclist as well. Perhaps the cyclist was unable to swerve out of the way of the car door because he or she was riding too close to the parked car. Or perhaps the cyclist was difficult to see because he or she didn’t use reflective gear at night.

The Motor Vehicle Act requires that we open our doors carefully. Implicit in this is the acknowledgement that swinging a door into the path of a cyclist puts the cyclist in an impossible position. They may be forced to make a split-second decision of either hitting the door or swerving out into the path of another vehicle. Car commuters may have a difficult time arguing that they aren’t to blame.

It isn’t just the courts that take doorings seriously. Policymakers and cycling advocates have taken the lead. From a public-safety standpoint, some advocates promote what’s called the Dutch Reach when exiting parked cars: opening a car door with the hand farthest from, instead of closest to, the door. It’s a clever little move that forces you to swivel your shoulder back. While doing so, it becomes easier to see if cyclists are approaching. This message has some momentum. In fact, the U.K. has recently incorporated the Dutch Reach into their highway code for safe driving.

A word of caution: you should not act or rely on the information provided in this column. It is not legal advice. To ensure your interests are protected, retain or formally seek advice from a lawyer.The writer thanks Jesse Kendall for his insight on the subject.