"My heart is broken. I love you profoundly my dear friend. And I will miss you everyday. May flights of angels sing thee to thy rest," actor Zachary Quinto, who portrays Spock in the current "Star Trek" film series, said on website Instagram.
"He was a true force of strength and his character was that of a champion," "Star Trek" cast member Nichelle Nichols, who played Lieutenant Uhura, said in a statement. "Leonard's integrity and passion as an actor and devotion to his craft helped transport 'Star Trek' into television history. His vision and heart are bigger than the universe."