Death from Above!

Death from Above! is a side quest

Detailed walkthrough
Someone has initiated a nuclear missile launch. A blast zone will be marked on the map as a red circle, indicating the area that will be affected by the missile, which will land in the middle. A timer will begin counting down from three minutes. This time can be used to escape the blast zone or travel to its outskirts to witness the explosion.

Once the timer ends, the missile will descend on the targeted area and detonate in the blast zone, ending the quest as the trademark mushroom cloud rises over ground zero, and the area is soon cloaked in a cloud of radioactive fallout. Failure to escape the blast zone before the timer expires will result in immediate death. Being killed by a nuke for the first time unlocks an achievement.

Bugs
If the event Scorched Earth is active, player characters who have died from radiation three or more times will be spawned in the zone but will be immune to environmental rads. This works outside of blast zones in other highly irradiated areas.