All that said, if we were to be hit directly, it might not kill us all immediately! The downside is that's akin to not being killed by a nuclear blast but being close enough to know you're in trouble. In addition to the wave of immediate destruction, the rays would wreak havoc on the ozone layer, destroying it by 30-50 percent. So if the gamma radiation didn't get you, the sun's radiation would. It would also break up nitrogen molecules in the atmosphere, causing a blanket of smog and acid rain to form and cool the Earth significantly. Needless to say, these are all very bad things.