[Deaf Smith]

>>Did she reach for the handle to…

Was she a smoker?

Some smokers do all sorts of stuff to be able to light-up.

[CivilWarBrewing]

My guess is she reached for the handle to stabilize herself from the trailer getting a little wobbly and the wind-assisted door movement overcame her. I'm also guessing this was not sudden because she was found with the handle still in her hand which means she was using extreme grip in an attempt to try to close the door and she had the time to use all her might to hold onto that handle before breaking off.