Rettelse af mit resume? :)

Jeg har skrevet et resume af en dansk artikel, så vil jeg gerne have en engelsk kyndig til at kigge den i gennem med især fokus på det grammatiske :)

A 19-year-old man, who had been suspended from his school, decided that he wanted a bloodthirsty revenge on his former school named “Gutenberg” which is located in the former eastern Germany. The columbine claimed 18 victims. They were all killed with composure. The German chancellor Gerhard Schröder declared that he was very shocked by the columbine, and he said that he couldn’t by any stretch of imagination believe it. Two weeks prior to the columbine, the German people had been appalled by another disaster. 11 German tourists were killed by a bombing raid in Tunisia. The actual columbine at Gutenberg started around 11 AM when the school caretaker called the police because he had heard gunfire. A surviving pupil explained that he and his classmates had been making fun, and the teacher had allowed them to go outside to see what was going on. To their great surprise, the pupils saw a masked man who stood opposite of them. Armed police had found the shooter in a room where he had committed suicide. 700 young people were kept as prisoners at the school. They were too frightened to leave the school area. The minister of foreign affairs concluded that you have to ask yourself the question; what is wrong with a society where this can happen?