AceShowbiz -

Justin Bieber's hamster Pac passed away on Tuesday, March 12. Tori McClure, the lucky girl whom Bieber gave Pac to after his performance at a Jingle Ball in Atlanta last December, confirmed it with a short tweet, "Little hamster heaven."

Hours later, all Beliebers were grieving over the death of the Canadian heartthrob's hamster. They posted #RIPpac and made it to the top of Twitter's trending topics on Tuesday evening.

McClure took a chance to explain Pac's condition. "They say PAC probably won't make it much longer. He's like an old man. My feelings couldn't be more hurt ):," she tweeted. "But they also said 'on the bright side he got to live a healthy lavish life of a popstar, not many hamsters coulda been the Biebs' #feelings."

She also posted the hamster's last photo and wrote, "I just wish he could get better. One final picture! He was OUR baby & @justinbieber I still can't thank u enough." Promising to give the hamster a proper burial, McClure did not forget to thank Bieber and close friend Alfredo Flores for trusting her to take care of Pac. She wrote, "thank u guys for what u done for me. Having him was truly a blessing & a small beacon of hope! I love u guys!"

Bieber first introduced his favorite hamster in October 2012 through an Instagram photo. Two months later, the "As Long As You Love Me" singer was spotted handing over Pac to a female fan, who has now been identified as Victoria McClure, after his performance at the Jingle Ball in Atlanta and saying, "That's all you. You gotta take care of PAC."

Bieber, who is currently in Madrid, has not commented on the hamster's death yet.