Dunn, 34, was a cast member of the "Jackass" films and TV show.
Photos published online, apparently showing Dunn drinking alcoholic beverages and looking inebriated shortly before he hit a tree with his car Monday, prompted Ebert to say on his Twitter feed, "Friends don't let Jackasses drink and drive."
The comment sparked outrage from many "Jackass" fans, as well as Dunn's cast-mates, who said they felt Ebert had jumped to conclusions since alcohol officially hasn't been determined a factor in the crash that killed Dunn and a "Jackass" production assistant.
Tuesday, Ebert's Facebook page was taken down briefly, "in response, apparently, to malicious complaints from one or two jerks." It was restored later in the day.
In response to the outcry, Ebert attempted to clarify his stance on his Chicago Sun-Times blog Tuesday.
"To begin with, I offer my sympathy to Ryan Dunn's family and friends, and to those of Zachary Hartwell, who also died in the crash," Ebert wrote. "I mean that sincerely. It is tragic to lose a loved one. I also regret that my tweet about the event was considered cruel. It was not intended as cruel. It was intended as true. I have no way of knowing if Ryan Dunn was drunk at the time of his death. What I knew before posting my tweet was that not long before his death, he posted a photo on Tumbler showing himself drinking with two friends."
By 11 p.m. EDT Tuesday, hundreds of people had written comments, many of them supporting Ebert's initial message, on the Sun-Times Web site.