The 38-year-old singer's name was announced in the original lineup for the concert on Sunday, and though he sent in a video message of support that was broadcast during the telecast, some fans were left wondering why he didn't perform. Usher explained that he had an important family obligation to attend to on Instagram on Monday.
"So happy to see that last night's concert in Manchester proved that love always prevails," he wrote. "I would have loved to be there but it was my son's first day at Camp Kudzu, one of the few summer camps for kids living with diabetes. This was an important day for him and for myself as a proud father. Stay strong UK."
Usher also posted an Instagram video addressing the concert tragedy, which killed 22 people.
"My heart is with you, Manchester," the singer said in the message posted on Sunday. "I'm so sorry for all of your loss and the pain that you've gone through. ... We need to love each other. We need to be good to each other. Stay strong and united, because only through that love can we help each other heal."