The city of Ottawa is investigating after a trio of condo balconies collapsed Monday morning in a “pancake effect,” officials said.

Residents woke up to a crashing sound some thought was an earthquake to find the balconies on the ground in a pile of shattered glass and mangled wood. Two of the balconies appeared to be severed clean off the wall of the four-storey building at 235 Patterson Avenue, near Bank Street. They landed in the laneway leading to a parking garage, but no one was hurt.

“Obviously if people were on their decks it would have been really bad,” said Cpt. Steve Styles. “The top one let go and it had a pancake effect.”

City officials were alerted to the incident Monday morning and visited the scene soon after, officials said in a statement to CTV Ottawa.

“Building inspection staff have attended the site and directed the property owner to take immediate measures to prevent access to the balconies for the affected units,” the statement said. “There were no injuries and an investigation is ongoing.”

Though it remains unclear what caused the balconies to collapse in the first place, passersby were quick to speculate about the quality of the build. “I’ve heard about it with other places, in older buildings,” said one man.

“It’s a new building. It must not be engineered very well,” said another.

The last time inspection staff visited the building was in 2009 when it was constructed, the statement read.