Two of the teenagers were students at Birmingham Southern. Students there are in shock and disbelief.
On Wednesday, the president announced the school would help rebuild the nine churches that burned through resources and labor.
Meanwhile, fellow theater students remember Mosley and DeBusk as just normal kids.
Martin Landry, a theater student, says, "In the theater, you're a very tight-knit community and they were a part of that community. It wasn't 'oh, who are those guys, we don't want to talk to them'. Everybody trusted each other. We were very good friends."
David Pollick, Birmingham Southern's president, says, "This is not Birmingham Southern. It is not the character of the students who are here. It shocked me."