The bus was seen stopped near the intersection of Marine Drive and Lawrence Avenue in Uptown about 5:30 a.m.
RELATED: Boy, 3, killed after being hit by school bus in Cary
Chicago police did not immediately provide information about how the crash occurred or if anyone was injured.
CTA said 81 Lawrence buses were temporarily rerouted via Lawrence, Clarendon Avenue, Wilson Avenue and Marine Drive east and Marine Drive, Foster Avenue, Sheridan Road and Lawrence west.
This is a developing story; check back with ABC7 Chicago for updates.