Which event served as a signal to the jews in germany and austria to leave as soon as possible?

There were many signs like laws were passed refuting Jews citizenship, prohibiting them to marry non-Jewish Germans. One of the far ahead signs was a very big one the Kristallnacht (night of the broken glass) was an intensive violence on Jews and their places of business, destroying, looting, and arresting. Unluckily, because of the amount of people who wanted to go out of Germany, many countries were hardening their immigration policies, so it was often hard for them to find a place to go.