In the wake of last week’s terror attacks in Paris the world continues to mourn the many lives lost. Justin Bieber is one of the many mourning a personal loss of a friend or family member and took to Twitter to express his feelings. Thomas Ayad, a Mercury Records product manager, was one of the 89 killed during the mass shooting at the Eagles of Death Metal concert. Justin Bieber revealed in his message that he had the opportunity to work with Ayad for 10 years and wished thanked him more often. He advised his fans, “Make sure to appreciate people while you have them.” Read the full message in the gallery.