The tree fell over about 11:10 a.m. and a large chunk of it landed at the intersection of 89th and Wallace streets, according to fire department spokesman Larry Langford.
A woman in her 70s was injured by the incident and taken to Little Company of Mary Hospital and Health Care Centers in Evergreen Park in good condition, said Langford, who wasn't sure if the woman was walking or inside a car.
The tree also fell onto power lines, said Langford.
As of 11:30 a.m. firefighters had left the scene but crews from the city's Dept. of Streets and Sanitation were still trying to remove the tree from the road, according to Langford.
Police News Affairs Officer Michael Sullivan said police were guarding the scene.