It would be a hard thump, but probably not to bad... I won't be doing that again if I can avoid it... I was probably about 16' off the ground.
Safety is my number one concern, but after 3-hours, just getting the heck out there became my number one concern...
That's why I was working on a weekend so that no one else would be around.
I think if I get stuck doing this again, I will hire a friend to help move that thing around...