Simplify the following text for a Grade 11 native English-speaking person.
Original: Dollfuss was assassinated on July 25 , 1934 by ten Austrian Nazis ( Paul Hudl , Franz Holzweber , Otto Planetta and others ) of Regiment 89 who entered the Chancellery building and shot him in an attempted coup d' Ã tat , the July Putsch .
Simplified: On July 25 , 1934 eight Austrian Nazis entered the Chancellery building and shot and killed Dollfuss in an attempted coup , as a prelude to Anschluss .