Florida International linebacker Luke Knox has died. He was 22.

Knox’s death was announced Thursday morning by FIU coach Mike MacIntyre. The coach did not reveal Knox’s cause of death.

“Words cannot express the heartfelt sorrow we feel because of the passing of our teammate and friend, Luke Knox," MacIntyre wrote. "I had the honor of coaching Luke at Ole Miss and at FIU. While I admired his passion for football, his genuine love for his family and teammates is what I will always remember. He had a special way of making everyone around him feel comfortable and confident. Luke’s family is special to me and they will continually be in my heart and my prayers during this difficult time. On behalf of the entire FIU football family, I extend sincere condolences to Luke’s family and all who love him.”