Selena Gomez says the death of her longtime friend Christina Grimmie has left her heartbroken.

“My heart is absolutely broken,” the singer wrote alongside a photo of the pair on Twitter. “I miss you Christina.”

Grimmie, who developed a following on YouTube, was discovered by Gomez’s stepfather Brian Teefey in 2010. After the singer released her first EP a year later, she became a supporting act for Gomez during the U.S. leg of her We Own the Night tour. Following her presence on The Voice season 6, Grimmie reunited with the “Hands to Myself” singer for her Stars Dance tour in 2013.

The two also featured in a promo for the Xbox 360 Kinect console in 2011. Watch it below.

Grimmie praised Gomez and her family during a 2011 interview with Seventeen magazine. “I’m so blessed that they’re in my life,” she said. “They’re literally like a family — Selena has been so encouraging ever since we got hooked up. It’s crazy! It’s very much a fairy tale.”

Grimmie was shot after a show in Orlando, Florida, and later died due to her injuries. She was 22 years old.

Following her murder, Teefey created a GoFundMe page in support of the singer’s family.