Soratobu Tire

A tire comes off a moving truck and becomes a deadly weapon, hitting a mother and child. The problem was caused by the vehicle manufacturer's failure to recall the vehicle, but the blame falls on the head of the delivery company who, despairing, searches for evidence that the recall was suppressed. Crossing paths with banks, police, weekly magazine writers, the victim's family, and various others, he eventually gets to the truth of the matter.

(Source: MyDramaList)