PASADENA - A historic football rivalry is missing its enduring symbol and traveling trophy, the Victory Bell, after an ongoing but fruitless investigation into its theft.

John Muir and Pasadena high schools have squared off in epic football battles for more than half a century, ever since they were the only secondary schools in Pasadena. Their game is called the Turkey Tussle because it was originally scheduled on Thanksgiving Day. This year's game is at 7 p.m. Thursday at the Rose Bowl.

At stake is the opportunity to dominate rivals in front of thousands of spectators, including many alumni, at the historic stadium. Bragging rights are on the line. But the players also compete for the illustrious bell, which is awarded to the victors until the following year, when the two teams play again.

Thursday, for the first time in 50 years, the post-game celebrations will not include players gleefully clanging the bell. It was stolen months ago and school officials have no reason to think it will be recovered.

"That bell is an important symbol," said Derick Evans, principal of Pasadena High School. "It is more than just a bell. It is that symbol that people are able to connect to."

The Victory Bell has only been housed at Pasadena High School for two of the past 20 years, which might make it even more valuable to Evans.

Evans used the Victory Bell as a motivational tool to rally students and parents at Back to School Night and at assemblies. If Pasadena High School won the bell, which has not happened in the four years Evans has been at the school, he said he would hold a special assembly to celebrate.

The bell helped unify the community, Evans said.

"I would really hope that someone, knowing the tradition and how important it is, could leave it someplace," Evans said.

George McKenna, assistant superintendent of the Pasadena Unified School District, said he initially thought stealing the bell was a prank. Now he thinks it may be truly gone.

The Victory Bell was given to Pasadena High School in the 1950s by a parent who worked for the Sante Fe railroad, said Bob Beran, one of school's athletic directors. It replaced a large wooden hammer called the Governor's Gavel, the original trophy. The Victory Bell is about 20 inches in diameter and weighs about 400 pounds, district officials said. It rests on a wheeled cart.

Muir has dominated the contest in recent years, so until its theft the bell was housed in a trophy case at the school at 1905 Lincoln Ave. Sometime between June 10 and 13, the weekend before graduation, vandals broke into the school, shattered the trophy case and carried the bell away, said Daniel Webb, principal of Muir.

The suspects also spray-painted "PHS" and swastikas in blue paint at various places in a hallway, Webb said. District officials estimated damages at about $4,000. But officials said they do not suspect anyone from Pasadena High School stole the bell.