In a complete shock, it has been announced that John Cassaday has passed away. He was just 52. Cassaday’s sister shared the heartbreaking news earlier today. He was admitted to the ICU in New York four days ago and the cause of his death is unknown.

Cassaday was a beloved artist working for numerous publishers and making his mark on comics with series such as Planetary, Astonishing X-Men, Captain America, Star Wars, and more.

Self-taught, Cassaday was first published by Boneyard Press and Caliber Comics. It was a meeting with Mark Waid in 1996 where his career really took off. Waid shared his memories on the loss:

My dear friend John Cassaday passed today at the absurdly young age of 53 and I miss him already.

I met John in, I believe, 1996–Google will not give up the secret of exactly which year the Big Apple Comic Con was held at Madison Square Garden. John was pleasant, he was polite and well-mannered, and when he showed me his portfolio, I also knew he was tremendously talented for a newcomer. The next morning, I was having breakfast with writer Jeff Mariotte, who mentioned he was looking for an illustrator for his next series, Desperados. Boy, did he say that to the right guy, because I had just the artist in mind.

Outside of that fortuitous referral, I refuse to take any real credit for “discovering” John Cassaday. I can’t take credit for having functioning eyeballs. But we were friends forevermore after that, and watching his quick ascension to becoming one of the most gifted, most sought-after comics illustrators of his generation was a blast. John had a memorable stint on X-Men and another on his favorite character, Captain America, but it was Planetary that rightfully put him on the map. He was meticulous, he wouldn’t turn in a single piece of art until he’d worried it to death, and as his publisher for a brief time at Humanoids, I had the great and now melancholy pleasure of watching magnificent pages, his best ever, come in slowly on his dream project, an unannounced creator-owned multimedia series that will now be his unfinished symphony.

Men in comics, as a general rule, are not exactly blessed with leading-man looks, but John was. Ask anyone. Between his handsome appearance, his charming manner, and his perfect blend of confidence and humility, he was quite the favorite of many, many ladies in his youth. Many. Effortlessly. To walk into a room of women with John was a reminder that the rest of us really, truly needed to work on our game. My single favorite memory with John was when he and I and a bunch of other comics dudes were standing around a big convention bar-party when actor Michael Rosenbaum walked in. Every woman’s head turned, instantly, every eye upon Rosenbaum. It was like throwing a magnet into a box of iron filings. Conversely, every man in the bar who’d been there with a date was suddenly holding two drinks. In the tumult, I had the presence of mind to look at John and say, “Now you know how WE feel.”

John Cassaday, I will say without hesitation and with very little fear of disagreement, was one of the very best illustrators and storytellers to ever work in the comics medium. Like Neal Adams, Jim Steranko, or Michael Golden, he is a touchstone, a reference point to the dozens and dozens of artists whose work was influenced by his. Most people are lucky if more than a dozen people are still talking about them a month after they pass. My friend John will be talked about and remembered by an entire industry for ages. And rightfully so. Rest in peace, sir.

We’re absolutely shocked at the loss and a hell of a talent at such a young age. Our thoughts are with his family, friends, and fans.