At least 11 patients, including several elderly people, were killed in a fire that engulfed a private hospital in Rio de Janeiro, officials said Friday.

The fire at Badim Hospital in northern Rio de Janeiro, which was caring for 103 patients, began around 6:30 p.m. Thursday. The suspected cause was a generator that short-circuited, according to investigators.

As the flames spread, hospital staff and neighbors worked frantically to evacuate the building. Scores of patients who made it out were placed on mattresses laid on the street as officials and relatives arranged to take them to other medical facilities.

The blaze was the latest in a series of fires in Rio de Janeiro that have raised questions about faulty wiring and other hazardous conditions in buildings in the city.