An Evanston woman remained in critical condition Monday afternoon after a fire ripped through her apartment over the weekend.

The fire started Saturday afternoon in a first-floor apartment at 808-810 Oakton St., in south Evanston. The blaze left Sally Ewing, 43, with second- and third-degree burns on 50 to 60 percent of her upper body, said Alan Berkowsky, division chief of the Evanston fire department.

Ewing, who firefighters found in the apartment’s dining room, was taken first to St. Francis Hospital in Evanston and then to the Loyola University Medical Center burn unit in Maywood, west of Chicago.

Paul Degener, 78, who had been sleeping in his second-floor apartment when the fire started, was taken to St. Francis for treatment of smoke inhalation.

Firefighters took both Ewing and Degener out of the building through the rear entrance, since the front entrance was blocked by the fire. Three other residents were rescued from the building unharmed.

When firefighters first arrived at the building, they saw the fire in the first-floor apartment living room and learned there were still people trapped inside, Berkowsky said.

“Obviously, our main concern at that point is lives,” he said. “It was a very hot, smoky environment.”

Berkowsky said he did not know the cause of the fire, but he said it started while Ewing sat in a chair in the apartment.

“We don’t know what the ignitions were at this point,” he said.

Berkowsky estimated the fire caused $45,000 in damage, mostly to the first-floor apartment. Firefighters contained the blaze quickly, preventing it from causing serious damage to the upper floors or spreading to nearby buildings. Residents at 800-802, 804-806 and 808-810 Oakton St. were all evacuated.

The fire was still under investigation Monday.