Daniel Stern penned a heartfelt message to his "Home Alone" co-star, John Heard, who died on Friday at the age of 71.

In a lengthy letter shared on Twitter, Stern, who played Marv Merchants in the "Home Alone" franchise, began by writing how Heard was "the coolest cat in New York" and how "every actor wanted to be as intense as him." Stern continued by sharing how Heard was the first person he knew to be in a movie and how he learned how to act from "watching John do it."

Calling Heard his "big brother," he also recalled how the actor would take him and his wife, Laure Mattos, out for dinner at least once a week when they "were extremely broke" and how great of a father he was. He even wrote about how he found it funny that Heard was referred to as "Home Alone actor" since he "never remember[s] that John is even in that movie."

"I've only ever really watched it once, and he and the family were all so great in it," Stern wrote. "But we never had any scenes in it together and we only crossed paths on the set once or twice."

"But nothing was more intense than John's performance in Life. He lived it hard, fast and fearlessly. He was a romantic and a raconteur. He was as loyal and generous as they come. He was a friend and a brother and a legend in his time," Stern expressed.

Heard was found dead in a hotel in Palo Alto, California, reportedly recovering from back surgery. The cause of death is still under investigation.

After the news of his passing was confirmed, countless friends, co-stars and celebrities took to social media to honor the late actor.