Derbyshire,
United Kingdom 
why has my sumach tree fell over?It rotted at ground level
19 Aug, 2010
Answers
If it wasn't elderly, then some kind of damage has occurred at the base, allowing something like root and butt rot to take hold.
19 Aug, 2010
I'd be surprised if it doesn't send up a new shoot from the base or nearby so don't be too hasty to remove the rootball.
20 Aug, 2010
Oh dear - was it an elderly one?
19 Aug, 2010