Calgary Tower closes during repairs, investigation after dramatic elevator rescue

The Calgary Tower has closed to the public while repairs and an investigation are ongoing after one ofits elevators broke down, requiringa dramatic rescue by first responders.

On Friday evening, eight people had to climb out of the ceiling of the brokenelevatorbefore being lowered into a second functioning lift that was brought alongside, in what's called a "high-angle rescue."

What exactly happened leading up to the events of Friday night is still being determined.

The sounds heard by the occupants of the elevator led themto believesome of the cables holding the elevator broke. On Saturday, the Calgary Fire Department said first responders on scene saw evidence that two of the six cables had indeed snapped.

• 'We heard the cable snap': Firefighters rescue 8 in nerve-racking Calgary Tower elevator extraction

The Alberta Elevating Devices and Amusement Rides Safety Associationconfirmed to CBC News that they are in the midst of an investigation of the incident.

On Monday, after closer inspection, the association said it had determined that two cables broke.

The association is the provincial body that ensures all elevators and other elevating devicesin Alberta comply with safety codes and standards.

The elevator was last inspected in July 2018, bringing it inside of the two-year requirement of provincial standards, according to the association's records.

When cables snap, 'something catastrophic has happened'

"So in best practice, the cables will never snap. They'll be inspected so that they they don't snap," said Lonnie MacKenzie, the CEO of Abco Elevator.

Abco Elevator operates in Alberta but is based in Regina. MacKenzie is not involved in the investigation of the Calgary Tower but agreed to speak to CBC News about safety protocols and what might have happened.

"If they do snap, something catastrophic has happened."

MacKenzie said he's interested to hear what the investigation turns up because incidents where cables snap are so rare.

"When something like that does happen, generally the cables have deteriorated."

The Guardian reported on anincident that happened in Chicago in 2018 whenone of the cables snapped in a highrise building and the lift dropped 85 storeys.

MacKenzie saidthere are independent safety mechanisms in place for when cables break. The chief one isthe "governor cable,"which acts as a fail-safe and should bring the elevator to a complete halt if the worst happens.

The Calgary Tower issued a press release Monday that said the emergency systems did work as they were supposed to.

As far as the high-angle rescue that was required to get the eight people out of the elevator car, MacKenzie said that would be the least preferred method. Generally, the best practice is to move the elevator instead of removing the people from it.

However, MacKenzie said that because the event tookplace in the 56-storeyCalgary Tower, there would have been aunique set of circumstancesbecause there are so few floors to which the elevator could be moved up or down to reach.

Calgary Tower issues apology

Monday afternoon, the Calgary Tower issued an apology in an emailed statement.

"We are truly sorry for the experience of the guests involved and any distress it may have caused," it read. "The Calgary Tower will be closed while the investigation continues. The Calgary Tower will reopen when we are satisfied that our elevator systems are functioning reliably.

"We are taking this matter very seriously.The CalgaryTowerremains committed to safety excellence and is dedicated to ensuring that this landmark can be enjoyed safely by the public."

More information is expected to be released regarding the investigation in the coming days.