Complex sentence: At the 2006 Vancouver Zombie Walk, an incident occurred in which two impatient drivers attempted to drive their cars through a crowd of zombies headed down Robson Street: this resulted in some severe injuries among the zombies, but no damage to the vehicles.
Split into simpler sentences: At the 2006 Vancouver Zombie Walk, an incident occurred in which two impatient drivers attempted to drive their cars through a crowd of zombies headed down Robson Street. This resulted in some severe injuries among the zombies, but no damage to the vehicles.