Other elemental damage also gets carried to you.
example: Lightning bolts, fire balls, frost novas, poison explosion. Cant really see how you died, but it must be have been the frost nova, the lightning dmg got you there(from frost nova) and you were already low on hp the moment the monster died
edit: lightning bolts got you low(through door) and frost nova+lightning dmg finished (what Zenstrader said)
edit2: Lightning bolts came into your direction

if you play it slowly(they show up) +cold damage
This post was edited by DEngineer on Jul 13 2018 10:31am