1. Martin Luther King Jr.'s mother was killed in church.
From wikipedia about Martin Luther King, Sr.:
His wife Alberta was murdered in June 1974. She was sitting at the organ of their church when she was shot. King Sr. continued to serve as pastor of the Ebenezer Baptist Church until 1975.
In 1969, King Sr. was one of several members of the Morehouse College board of trustees held hostage on the campus by a group of students demanding reform in the school’s curriculum and governance. One of the students was Samuel L. Jackson, who was suspended for his actions. Jackson subsequently became an actor and Academy Award nominee.
And more recently, the Unitarians in Knoxville killed.