A worker is hoisted to the roof of a downtown Regina tower after being stranded for several hours. (CBC)

Two Regina maintenance workers who were stuck on a scaffold 19 storeys above ground are safe and sound after a dramatic rescue Friday morning.

The rescue started shortly after 10 a.m. CST outside the west tower of the twin towers on the Scarth Street mall downtown.

However, office workers on the 19th floor said the men had been there since about 8 a.m.

"We were wondering why they were just sitting out there," Cindy Howden said. "We thought they were on a break or something. They didn't knock on the window to let us know."

A rescuer from the Regina fire department, seen on the left, attaches a line to a stranded worker so he can be hoisted to the roof. (Dani Mario/CBC)

It wasn't immediately clear what had caused the problem, but it appeared to be a stuck cable.

The contract workers had been hauling air conditioning equipment to the roof on the 22-storey building, which is one of the tallest in Saskatchewan.

The temperature was around zero Celsius, but it could have been worse — earlier in the week the mercury was down to around -35C.

Around the downtown, groups of people looked up at the drama unfolding above them.

A CBC reporter on the 19th floor could see the men through a window and they appeared calm. When the reporter asked what the problem was, they pointed to a cable box.

A firefighter attached to a line was able to drop down and pull them to the roof, one at a time.

"They lowered me down, I just hooked into him and the guys brought him up," said Greg Treleaven, who's with the fire department's rescue team.

By 11 a.m., both men were back on solid ground. No one was injured.