ROSEMONT, Ill. -- Gale Sayers drew one more thunderous ovation from the Chicago crowd.

Six Hall of Famers and 230 past and present players and coaches were on hand as the Chicago Bears kicked off their 100th anniversary celebration weekend on Friday. When Sayers was wheeled onto the stage, the roar from the crowd could have drowned out the jets at nearby O'Hare International Airport.

Weakened by dementia diagnosed five years ago, Sayers still made the 130-mile trip from his home in Wakarusa, Indiana.

He showed up wearing his gold Hall of Fame jacket and a blue-and-white cap with the No. 40. He wiped his left eye as his old teammate Dick Butkus, Dan Hampton and Richard Dent stood clapping onstage.

Moments later, Mike Singletary came out. And with Mike Ditka also there, the Bears had six Hall of Famers onstage at once.

When it was time for the group to leave a few minutes later, Sayers hunched over as Singletary wheeled him away. It was hard to tell if he was weeping. But there might have been a few tears shed in the room.

"That's a tough thing," Butkus said. "I call and check on him quite frequently, and it's a sad deal. You've just got to be thankful with what you've got. I've got my problems with neuropathy and my balance. But I've got no pain. At least I still know who I am. I'm happy about that."

Sayers' situation makes this weekend, in some ways, a bittersweet celebration.

The "Kansas Comet" was a two-time All-American for the Jayhawks and dazzled with the Bears in a career that lasted just seven seasons because of knee injuries. He was a five-time All-Pro who remains the youngest player to be inducted into the Pro Football Hall of Fame, enshrined at age 34 in 1977.

Gale Sayers, shown here while being introduced during the Pro Football Hall of Fame enshrinement ceremony in 2014, was in attendance Friday night as the Chicago Bears kicked off their 100th anniversary celebration weekend. AP Photo/David Richard, File

He was Rookie of the Year in 1965 after being drafted one spot behind Butkus with the No. 4 overall pick. He scored six touchdowns in a win over San Francisco at muddy Wrigley Field that season and made four Pro Bowls before hanging it up in 1971.

"He looked like he was gliding," Ditka said. "I mean, the field was muddy. Everybody was slipping and sliding, except him. It was the most unbelievable exhibition I've seen in the history of the game. There probably was nothing like that. Just a great, great guy. Great guy. Gale was humble, never said a whole lot. But he was a super football player."

Ditka was glad to be part of the festivities. The Hall of Fame tight end and iconic coach of the 1985 Super Bowl champion Bears had a heart attack on a golf course in November.

He said he has cut back on smoking cigars, often opting to chew an unlit one instead.

"Life is a gift from God. And what we do with it, he's going to give back to you," Ditka said. "I'm hoping he'll give me a few more years around, and I'll try to do the best I can with it."

For Gary Fencik, the two-time Pro Bowl safety who played on the Super Bowl championship team, being a part of an event like this is special. He is from Chicago and holds Bears season tickets.

"It is," he said. "And you don't really think about that you're part of the history of any organization. ... It's not that I haven't read about the Bears' history or the NFL. But this gets you a little more focused on that -- and that you are a part of a very important fabric to the city and the NFL."

Jim McMahon, the "Punky QB" on the '85 team, called Chicago "a special place."

"I've always loved this town, lived here for 28 years -- almost half my life," he said. "All my kids were born and raised here. It's a special place. And this was a special team that I was involved with."