Oregon College Shooting: Maroon 5, Charlie Puth, Lance Bass & More Stars React

Mike Sullivan/Roseburg News-Review via AP
Police search students outside Umpqua Community College in Roseburg, Oregon on Oct. 1, 2015, following a deadly shooting at the southwestern Oregon community college.

"When will this stop? This is madness."

Celebrities took to Twitter on Thursday (Oct. 1) to share their thoughts and condolences over the mass shooting at an Oregon community college.

As many as 13 people have been killed and 20 more injured, according to multiple reports.

The shooting took place Thursday morning at Umpqua Community College near Roseburg, Ore.

This article was originally published by The Hollywood Reporter.