It’s called rooftopping and it’s a phenomenon that has grown with the tide of social media.
Perhaps the highest profile example of this in Canada occurred in April, when 23-year-old Marisa Lazo scaled a crane at TMG Builders' 50 at Wellesley Station, a 37-floor condo and retail project at Wellesley and Yonge Streets in downtown Toronto.
Lazo, who faced several criminal charges, climbed the equivalent of 12 storeys in the middle of the night, slid down a cable as far as the hook block, where she was spotted sitting nonchalantly.
Toronto Fire Services rescued the woman, with Capt. Rob Wonfor rappelling down to reach her, taking her to the ground where she was charged with several counts of public mischief. Lazo reportedly had a history of high risk climbs.
On Aug. 2, Toronto police and firefighters had to deal with another construction crane climber at a downtown worksite at Dundas and Jarvis Streets.
And then in July, at a Seasons retirement home project in downtown St. Thomas, Ont., a 29-year-old man, reportedly on a dare, scaled to the top of a 45-metre crane. The man was coached down by emergency responders and charged with mischief and breach of conditions for consuming alcohol.
Toronto Police Const. David Hopkinson said rooftopping is hardly unique to Canada but has been a worldwide phenomenon for several years, not just on construction sites but atop finished buildings and bridges.
Hopkinson said the behaviour goes by different names, including "slacklining" where culprits string a cable between two buildings and tightrope across, which can pose danger to the public below because lines can be hooked into rebar and dislodge brittle concrete.
Hopkinson said construction sites are "dangerous places" and not for the public. While contractors attempt to secure sites "unfortunately many of them can be defeated."
Criminal charges for this behaviour can vary.
"If you're defeating the lock on a building, that's mischief," Hopkinson said.
"If you're entering an area that you are not allowed to be in, that can be considered break and enter. Most of these are trespassing at the least."
Anabel Quan-Haase, a Western University professor who studies how people use social media, said rooftopping and other high risk behaviours are the result of people bragging of their exploits to their social media audience, on platforms like Facebook or Instagram.
"You've got this really large audience, whereas before maybe you had your five friends, but now (with social media) you've got a potentially global audience," she said.
An UrbanExploration guide on Reddit provides highly detailed tips from a seasoned rooftopper.
For example, "Buildings with construction on the tops have roof that are always open but elevator won't go up (buttons won't work) so spam buttons to highest possible floor get off and go up. Beware of lingering workers go late (sic)."
And, "Be careful when going into active construction sites. I wear big heavy boots and sometimes will nab a helmet off a dump truck because I have gone in and tripped over stuff and had wires fall on me at night alone."
But the industry is more than aware of the phenomenon and officials say they are doing their best to increasingly secure sites.
John Mollenhauer, president and CEO of the Toronto Construction Association, said he drove by the Wellesley project "wondering if they had taken adequate precautions (and) it looked to be like they had done everything one could reasonably be expected to do to keep the public away."
Under the Ontario Occupiers Liability Act, builders may not have to protect trespassers from danger but they can't create a danger or act with reckless disregard.
According to a blog post by Vancouver-based Radius Security's Susanna Chu, "It is not difficult to imagine a hazardous scenario where a trespasser is killed or injured, leading to a lawsuit against the owner and contractor. Even if the suit does not succeed, public relations could suffer and insurance rates may rise."
Mollenhauer said contractors are mindful of this and therefore "go way above and beyond what they are obligated to do in terms of health and safety."
And, he said, "they look as well to protect the public."
Mollenhauer explained safety is a continual industry discussion, the importance of which is shown in May Safety Month and the League of Champions, a joint industry and government program to promote worker safety and change the culture around safety.
"Nobody wants to turn on the evening news and find out that some crazy person has found their way somehow onto their job and onto climbing a crane," he said.
Grant Cameron, communications director for the International Union of Operating Engineers Local 793, which represents and trains crane operators, said rooftopping "could impact overall safety and endanger the lives of operators and other workers if the equipment has been interfered or tampered with by unauthorized people."
Adam Carapella, vice-president of another condo builder, London-based Tricar, said his company takes extra steps to keep its sites safe, such as securing crane hatches and using padlocks that are resistant to bolt cutters.
But Mike Baxter, business development manager for Radius Security, said conventional security methods give a false sense of security.
He said security guards and conventional CCTV cameras most often can't capture a trespass quickly enough.
"A security guard, oftentimes they're sitting in the site trailer, or they're on the other side of the site," he said. With CCTV, "people just have cameras and they're recording and so a person climbs up the crane, they leave, they may hear about it the next day."
Baxter said his company's Redhanded human detection technology operates on the basis of algorithms, differentiating between human and non-human activity. Once someone enters a site, that individual's image is captured and a signal sent to indicate a crime in progress and alert police.
Baxter said his company has a former police inspector in Toronto working for it.
"Most of the security industry is quite a burden on police — lots of false alarms," he said.
"And for us, we're trying to change that. We're trying to be what we call a force multiplier so we're actually doing something that helps police to make arrests."