Question In the event of a cargo fire, opening trailer doors may cause a fire to expand because: Answers Oxygen will be allowed into the area. The temperature of the trailer will change. It will provide moisture. It will provide more light. Explanation In the event of a cargo fire, you should not open the trailer doors. Doing this could cause the fire to flare up by giving it access to more oxygen. Take a FREE Practice Test Now This questions appears in the following tests: Massachusetts HazMat , Oregon HazMat , South Dakota HazMat , Wyoming HazMat ,