Selena Gomez Honors Christina Grimmie in Miami: 'I Don't Really Understand How This Really Happened'

Selena Gomez performs onstage during her Revival Tour
Mark Horton/WireImage

Selena Gomez performs onstage during her Revival Tour live at the Canadian Tire Centre on May 22, 2016 in Ottawa, Canada.  

Selena Gomez broke down in tears at her concert in Miami Saturday night (June 11) as she paid a moving tribute to her late friend Christina Grimmie.

The singer got emotional while performing her song “Nobody” and mouthed the words “I’m sorry” to the crowd. She then gathered her composure to talk about The Voice star, who was murdered by a man believed to have been a deranged fan as she signed autographs for a meet and greet after a show in Orlando.

Christina Grimmie's Manager Creates GoFundMe Account For Late Singer's Family

“When she was 14, we met her and my parents and I signed her,” Gomez said, her voice quivering as she spoke. “One thing about Christina and her family is that she holds her faith so closely to her. And I think it’s not about a religion and it’s not about anything or good deeds. It’s just that she had faith, and I don’t really understand how this really happened, but I would like to dedicate this next song to her.”

Seated at a piano, Gomez delivered a moving version of Hillsong Worship’s song “Transfiguration” in Grimmie's memory.

Prior to the show, Gomez canceled her own meet and greet because of security concerns.

Christina Grimmie's Brother Pays Tribute to His 'Superstar' Sister

Grimmie -- a YouTube star who placed third on the sixth season of The Voice -- was shot and killed by 27-year-old Kevin James Loibl at the Plaza Live on June 10 after her show opening for the band Before You Exit. Loibl was quickly tackled by Grimmie's brother Mark before shooting himself.

A candlelight vigil honoring Grimmie's memory will be held in her hometown of Evesham Township on Monday night (June 13).

Watch Gomez's tribute to Grimmie below: