Following a trial that lasted more than two years, at which more than 80 witnesses testified about the disaster at the opening ceremonies of the "Jewish Olympics," a three-judge panel found the five guilty of negligence.
The offense can carry up to a four-year jail term, according to a prosecutor. Sentences will be handed out at a later date.
The five who were convicted Monday were Baruch Karagula and Yehoshua Ben-Ezra, the contractors; Micha Bar-Ilan, the bridge's engineer; Adam Mishori, the head of Irgunit, the firm that subcontracted to Baruch and Karagula; and Yoram Eyal, the head of the organizing committee for the international games.
Two Australian athletes were immediately killed July 14, 1997, and hundreds of other participants at the games were injured when the pedestrian bridge in the city of Ramat Gan collapsed, plunging scores of people into the Yarkon River.
Two more Australians died weeks later as a result of complications linked to contaminants in the river, and dozens of athletes who were injured in the bridge collapse later suffered illnesses.
A week after the collapse, an Israeli commission found that the accident was caused by a chain of failures involving the bridge's planning and construction.
In October 1997, an Australian newspaper that had tests conducted on the river's water concluded that the athletes "fell into a deadly cocktail of chemicals and pollutants" resembling "diluted sewage."
Many of the Australian athletes have filed lawsuits against the games' organizers, the Maccabi World Union and the builders of the bridge, demanding damages for injuries, mental anguish and loss of income.
Ehud Stein, a lawyer representing the athletes, said Monday's ruling could prove decisive in the civil lawsuits.
Announcing Monday's decision, the panel said that there had been a complete lack of coordination between the parties responsible for building the bridge.
Eyal, the head of the organizing committee, sounded a repentant note after the verdict was read.
"The regret and pain of the incident will certainly accompany me and my colleagues in Maccabi until the end of our lives," he said. "We just hope the lessons will be learned and compensation arranged quickly, because the suffering of the families is awful."
He also described the Games as a "great Zionist enterprise" that he hopes will "continue to exist in the future."