A Gamma Ray Burst hits Earth

Not to mention any names... In March of this year I finished this book for the proof readers to work on. The book went live at amazon.com in May. It was my belief that the next president of the United States would be a woman... See how she handles the situation of a Gamma-Ray burst hitting Earth. So why didn't the Earth turn into a glowing cinder destroying all life as we know it? This Gamma-Ray Burst does kill over half of the world's population and all other life on the impact side along with a considerable amount of damage to the atmosphere and living DNA. I call this GRB hit a 'fragmented GRB' hit. To my knowledge there is no NASA model for this type of impact but what if this could really happen?