A man on a motorized scooter is "lucky to be alive" after falling several stories down an elevator shaft in a downtown apartment building Thursday morning, Toronto Fire says.

The man fell through the elevator doors on the third floor, landing in the basement of a Toronto Community Housing highrise along Simcoe Street, in the area of Dundas Street West and University Avenue.

The man broke his leg and is now in hospital, fire officals say.

"He's lucky to be alive," said Platoon Chief Kevin Aucoin. "He fell about 45 to 50 feet."

About 25 firefighters were on the scene as a team rappelled into the passage to remove the scooter, and then rescued the victim using a harness, said Capt. Adrian Ratushniak.

"The scooter may have broken some of his fall," Aucoin said, adding the man was conscious but in a lot of pain. The man has a compound fracture in one of his legs, he noted.

'Wailing and screaming'

Paige Best, who lives in the building, heard "crying and wailing and screaming," she said.

"It sounded just horrific," said Best.

"I'll never forget that sound in my life."

An investigation is underway into how this incident could have happened, Toronto Fire says. (Kelda Yuen/CBC)

The man was trapped in the elevator shaft for about 15 minutes after fire crews received the call around 10:30 a.m., said Ratushniak.

An investigation is underway and an inspector will assess why the elevator shaft was accessible to the public.

Police are holding the scene at 248 Simcoe St. and an investigation is underway, Toronto Fire says. (CBC)

"It's an incident whereby something like this should not have happened," Ratushniak said.