Original sentence: Many hazards, such as rain, darkness, a blocked course (due to debris, water, or safety vehicles), a car on fire, or a multi-car crash (especially one that results in serious injuries or one that results in damage to walls, fences or the surface itself which require repairs) might prompt series officials to call for the red flag
Edited sentence: Many hazards, such as rain, darkness, a blocked course (due to debris, water or safety vehicles), a car on fire, or a devastating multi-car crash (especially one that results in serious injuries or one that results in damage to walls, fences or the surface itself which require repairs) might prompt series officials to call for the red flag