The co-creator of Wolverine and Swamp Thing, Len Wein has passed away. He was 69 years old. He was undergoing health problems and tweeted about his time in the hospital as recently as September 7th. The exact cause of death is unknown.

Wein was one of the most distinguishable faces in comics industry. Apart from creating Wolverine and Swamp Thing, he also resurrected X-Men series in 1975 with help of artist Dave Cockrum. He also served as Editor of DC’s critically acclaimed Watchmen. Gadget helper of Batman, Lucius Fox, was also created by him.

DC Comics confirmed the news following an outpouring of tributes from the comics community overflowed online. Diane Nelson, president of DC Entertainment said –

“Len Wein was one of the most welcoming people and legends in comics from the moment I joined DC eight years ago. He wrote or edited almost every major DC character — there’s hardly a facet of DC’s world that Len didn’t touch. I, DC, and the industry will miss him and his talent very much. Our love and prayers go out to Christine, his family, and his fans.”

Wein got his start in comics in 1968 working on DC’s Teen #18 Titans. His first Marvel work came in Daredevil #71 in 1970. From there, he continued writing anthology stories for both publishers, along with guest-spots on such titles as Superman and The Flash. Together with Bernie Wrightson, they created the supernatural superhero Swamp Thing in 1971’s The House of Secrets #92