A Winnipeg apartment building is in ruins after fire tore through it around 7 a.m. Saturday.

Fire crews had to use ladders to save several people from the Sherbrook Street building, located between Sargent and Ellice Avenues. Some tenants were forced to escape from their windows.

"The smoke was so thick that you couldn't even see," said Tyrone Thiessen who lived in the apartment building. "I put my hand out…and I couldn't see my hand."

Firefighters rushed into the building in what officials are calling a spectacular rescue effort. "We were able to search the building in really bad conditions," said Bill Clark of the Winnipeg Fire Paramedic Service.

Nineteen tenants living in the building were sent to hospital. Two were taken to hospital in unstable condition, they have since been upgraded to stable. One firefighter was also taken to hospital with a leg injury.

Fire officials don't know the cause of the blaze but police said they have a number of people in custody and some tenants are suspecting the fire was deliberately set.

"Something was sprayed in the air," said Ahmedel Gudu who lived on the first floor of the building. "When I was breathing I (felt) a burning sensation in my throat."

Gudu noticed several young people standing behind the building before the fire started. "Teenagers, ten of them…were waiting for someone to come out from the building," he said. "They were holding big sticks and I was scared for my safety."

Up to 50 people have been displaced because of the blaze because fire crews had to evacuate two neighbouring buildings impacted by the fire.

-With a report from CTV's Jeff Keele