On October 27, Grynszpan's family and over 15,000 other Jews, originally from Poland, had been expelled from Germany without any warning. They were forcibly transported by train in boxcars then dumped at the Polish border.
Like previous mention, Germany was looking for a way to get rid of the Jews, they wanted to get them out. Many Jews of Polish origin had come to Germany because conditions were much better there than in Poland. The Germans it will be easy to get rid of them.
Because of the murder of a German by Herschel Grynszpan,in one night, 1,350 Jewish synagogues were burnt to the ground or destroyed; over 91 Jews were killed; 30,000 Jews were thrown into concentration camps; 7,000 Jewish businesses were destroyed; and thousands of Jewish homes were ransacked.
The event is significant as it marked a major intensification of the persecution of the Jews in Nazi Germany. It was the first time that the Nazis used organized, widespread violence against Jews simply because they were Jews. It became clear that they were no longer safe in Germany. Those who were able to do so, left Germany after this.
It is called that because of the broken glass. In English 'Kristallnacht' is often referred to as the 'Night of the Broken Glass'. (The German 'Kristall' refers to the high grade 'crystal' glass often used at the time for shop windows).