Based on the context and the answer, generate a question. 

Context: Boy I ca nt believe this happened ! If I could turn around and kick myself i would lol ! I ' ve done it a million times without anything happening until ... on 7/25 I was unloading the truck and coming down from the liftgate with a cart full of oxygen tanks . Somehow the cart kept going right off the gate and took me with it .

Answer:

The tanks were heavy causing the cart pull away from the narrator .



Why did the narrator lose control of the cart with the tanks on it ?