The Sentient (a Post apocalypse Story)

On March 29th Jaxonville weaponry built and formulated a revolutionary bomb that had the power to terminate anyone within 2,500 Kilometers from the blast. Anyone from 0-3km of the blast died immediately, and anyone within 8km only had a 50% chance of survival.
The fight to survive keeps going as more of us try to cross the border, hoping to get help and safety in the Sentient.
Who will survive and who will die?