Her brother tackled the suspect to the ground before the suspect fatally shot himself, authorities said in a press conference.
Grimmie, who was the opening act for the band Before You Exit, was signing autographs near a merchandise table when a man armed with two guns walked up and opened fire on her, police spokeswoman Wanda Miglio said in a press conference.
Grimmie competed on season six of NBC's singing competition representing Adam Levine's team. The Marlton, New Jersey native ultimately came in third.
Blake Shelton took to Twitter to express the same shock and and disbelief as her millions of fans. "Just hearing about this.. Is this all true? Anybody know how she's doing?" Later, he tweeted "Praying."
#PrayforChristina quickly became the number one trending topic on Twitter as hundreds of fans expressed their support. The most recent Voice winner Alisan Porter and Ashley Tisdale were among those who tweeted following the news.