Celebrities, presidential candidates react to Charleston shooting on social media

"Heartbreaking." "Disgusted." "Tragic."

From actors to presidential hopefuls, people took to social media to express grief, shock and anger after nine people were killed Wednesday night in a shooting in Charleston, S.C.

Police say that a young white male entered a bible study at Emanuel African Methodist Episcopal (AME) Church, a historic black church, and opened fire. Clementa C. Pinckney, a reverend and Democratic state senator, was among the dead.

People are expressing their condolences and discussing the event on Twitter using the hashtag #CharlestonShooting. Presidential candidates joined the conversation. Jeb Bush cancelled his campaign appearance Thursday.