There are dozens of official water gauges, most operated by the Toronto and Region Conservation Authority, across the Toronto area.

When storms slip past the gauges, like the ninja storm of Aug. 7, precipitation is unknown.

On that evening, conservation authority staff were trying to assess the threat of the Black Creek, a repeat offender for flooding. The first “low level” alarm (from a water-level gauge) for Black Creek at Highway 401 arrived by text message at 8:45 p.m. But, as a debriefing report noted, the rainfall gauges showed little precipitation.

Still, Black Creek continued to rise. It peaked between 10 p.m. and 10:30 p.m. In 90 minutes, it would rise 3.5 metres.

Inside the elevator, where Freire and Otrin are trapped, the river water keeps rising. It is brown. Otrin watches big bugs paddling on the surface.

Unable to find a door release, Freire joins Otrin on the handrails, to keep their one cellphone dry. With no way out, no cell signal, Otrin begins smashing the escape hatch in the ceiling. His knuckles bleed. He uses the top of his head, trying to let a cell signal inside. The hatch opens a crack and Otrin shoves in Freire’s red leather journal to keep it open. Standing on the railing with water at chest level, Freire calls 911. Police and firefighters are swamped with flooding calls. Eventually, he gets through.

A few minutes after 11 p.m., when the water reaches their chins, Freire and Otrin hear voices in the basement hallway, which was filled with six feet of water, nearly reaching the top of the elevator. Two Toronto police officers heard the 911 dispatcher’s call for help. Still in uniform, they swim down the stairs into the garage hallway and use a crowbar to pry open the elevator door. Water rushes into the elevator and then sweeps them out. One officer drags Freire up the stairs until he can walk on his own.

It took months, but Otrin and Freire are ready to talk. “There almost hasn’t been a day when I don’t think of the incident to some degree … some days I think about it more deeply than others. Certainly, it changes your perception of life,” Otrin says.

“We went through a lot of recovery, adjusting, dealing with the events and self-reflection,” says Freire.

Freire and Otrin had a hard time working, focusing and sleeping. They sought help for trauma. They received calls from lawyers, but declined offers of representation to sue the building owner, who has since added a floodgate to the garage entrance and water sensors on the elevators. “He’s a good guy,” says Freire. “We decided to just move forward.”

Freire designed an elevator sensor that would detect water below and stop on a higher floor. It could be used on elevators in flood-prone areas to “save lives for less than $50 dollars worth of hardware,” Freire says. The Ontario Building Code does not require flood detection sensors on elevators, a city of Toronto spokesperson says.

Freire and Otrin looked at the drone business and questioned its impact.

Do they continue trying to build consumer drones or use their experience to find a different purpose?

The answer, Freire says, lies with clean energy to combat climate change.

They designed a drone that can fly up a wind turbine and video the unmoving blades to check for damage or necessary maintenance, collecting data which Freire says, will improve the mechanics and potentially save on electricity costs.

“I think we realized that if we were still here, we might as well do something that was meaningful.”