When the caster for Wall of Flame dies, the wall is considered to no longer be part of the fight, and drops from the turn order. This results in it fully playing out all of its remaining damage to any unfortunate enough to currently be in the wall, before disappearing.

 

I've had casters lay down a Wall of Flame only to die to a DoT tick and kill anyone they dropped the wall on right away, as my party was helpless to act or move out of turn.

 

Edited March 4, 20196 yr by error3

I'm glad you pointed this out but it's honestly hilarious