In 1991, Simonson began writing for DC Comics. She, artist Jon Bogdanove, and editor Mike Carlin launched a new Superman title, ' — a title she wrote for eight years until #86 in 1999. She contributed to such storylines as "Panic in the Sky" in 1992. Later that year, Simonson (along with Carlin, Dan Jurgens, Roger Stern and others) was one of the chief architects of "The Death of Superman" storyline, in which Superman died and was resurrected. It was during that storyline, in "The Adventures of Superman" #500 (June 1993), that Simonson and Bogdanove introduced their character Steel, who graduated to his own title in February 1994, with Simonson as writer until #31. The character went on to feature in an eponymous feature film starring Shaquille O'Neal in 1997. Simonson was one of the many creators who worked on the ' one-shot in 1996 wherein the title character married Lois Lane.