A Pittsburgh Port Authority bus threw a set of duals while in traffic, damaging at least two cars, according to a KDKA-TV report.
No one was injured in the Jan. 26 incident.
The rear of the 28X Airport Flyer dropped when the tire/wheel assemblies became detached, sending sparks into the air. The driver immediately pulled off to the side of the road, but the incident caused at least one car collision as drivers attempted to avoid the careening tire/wheel assembly.
There were some 20 people on the bus at the time, according to reports, but no one was injured.
The Port Authority and local police are investigating.