The shooting took place overnight during a concert at the Route 91 Harvest Festival, with reports of over 50 dead, and more than 500 wounded.
According to The Mirror, Carey had already been set to appear on GMB to promote her upcoming Christmas film All I Want For Christmas Is You.
“This is horrible. I pray for the victims,” Carey said, looking shocked.
A number of viewers reacted harshly to the image of Carey in her home, reclining on a couch in front of a Christmas tree, calling it “inappropriate” on Twitter.
Many more were critical of GMB for going ahead with the pre-booked interview at all.
The interview with Carey was cut short for a break, and did not return to her, instead switching to the breaking news.
Carey tweeted her thoughts to the victims and families of those affected by the shooting soon after.