1. Early departure: a truck driver mistakenly drives away while

a lift truck is entering, leaving, or inside the trailer.

3. Landing gear collapse: weak or damaged landing gear gives

way and the trailer pitches forward or falls to the side.

5. Trailer upending: the weight of a lift truck sends the trailer's

nose down, causing the rear end to move up and away from

the building.

2. Trailer creep: a trailer can move substantially under the

weight of a forklift entering and exiting a trailer.

4. Trailer pop-up: the weight of a forklift sends the rear of the

trailer forward and down, causing the nose to rise.