So my customer rogue party member got instantaneously deleted by a trap down at level 13 of the Endless Paths.  He had full Health and Endurance.  I looked at the combat log and everyone took a lot of damage and everyone took 1000 points of RAW damage.  Why was the only one that died?  Shouldn't everyone of died?  Nobody else even got knocked out...I spotted the trap but I Guess rounded the corner to quickly.

The trap is based on the level 6 wizard spell death ring which has a chance to kill instantly, it's only a chance though.  The area of effect is very large.