An underground parking garage in Windsor, Ont. collapsed suddenly on Thursday afternoon, sending one man to hospital with non-life threatening injuries and prompting city officials to declare a state of emergency.

A heavy crane was parked on top of the structure when it collapsed. Video of the garage showed five vehicles and the crane resting in a pit similar to a sinkhole.

The injured man is in his 20s. He was on the crane on the surface of the garage when the collapse occurred, and was reportedly conscious when emergence responders took him to hospital.

Meanwhile, a police team searched the underground portion of the garage and determined that no one was trapped in the rubble.

"At this point there's been no activity or any signs of life," John Lee, a spokesperson with the Windsor Fire Department, told CTV News Channel on Thursday afternoon.

At least one search dog was sent through the lower level of the garage, Lee said.

Officials declared an emergency so that they could summon a provincial search and rescue team from Toronto.

A nearby 35-unit apartment building was also evacuated due to safety concerns. The residents will be housed in a local hotel until engineers can determine whether the structure of the building is safe.

With files from The Canadian Press