Venn as it correct. You can save vs death each round. Fail 3 and you die;
"DEATH AND DYING
✦ Dying: When your hit points drop to 0 or fewer,
you fall unconscious and are dying. Any additional
damage you take continues to reduce your current
hit point total until your character dies.
✦ Death Saving Throw: When you are dying, you
need to make a saving throw at the end of your turn
each round. The result of your saving throw determines
how close you are to death.
Lower than 10: You slip one step closer to death. If
you get this result three times before you take a rest,
you die.
10–19: No change.
20 or higher: Spend a healing surge. When you do
so, you are considered to have 0 hit points, and then
your healing surge restores hit points as normal. You
are no longer dying, and you are conscious but still
prone. If you roll 20 or higher but have no healing
surges, your condition doesn’t change.
✦ Death: When you take damage that reduces your
current hit points to your bloodied value expressed
as a negative number, your character dies."
- Quoted from PHB1 page 295
