Selena Gomez tweeted about Cory Monteith's death Credit: Jason Merritt/Getty

Selena Gomez, like so many of her famous peers and fans, is in mourning. The actress, 20, costarred with Cory Monteith in 2011's Monte Carlo, and reacted to Monteith's sudden death in Vancouver on Saturday, June 13, with a touching tribute. "This hurts," the singer-actress tweeted, sharing a photo in which she and the Glee actor warmly embraced at the Kids' Choice Awards back in April 2011.

"I love you Cory," Gomez added. "Rest in peace. My thoughts and prayers are with you and your family." Thirty-one at the time of his death, Monteith was found in his hotel room at the Fairmount Pacific Rim Hotel on Saturday. The FOX star, who had been frank about his substance abuse problems in the past, entered a rehab facility for a month-long stay back in April. He and girlfriend Lea Michele celebrated his May 11 birthday together.

"Everyone is in shock," a Vancouver source told Us Weekly on Sunday. Just two weeks ago, Monteith "sounded good . . . Never saw this coming," the source added.

An autopsy will be performed on Monday.