Photo/IllutrationFans flock to the Ebisubashi bridge over the Dotonborigawa river in Osaka’s Chuo ward at 2:25 a.m. on June 25 after Japan's 2-2 draw against Senegal. (Mari Endo)

OSAKA--Football fans can sing, dance and hug to celebrate Japan’s performance in the World Cup--but they have been warned not to jump on the Ebisubashi bridge here to prevent an “earthquake of joy.”

Osaka Mayor Hirofumi Yoshimura made the plea ahead of the Japan-Poland match that will kick off late June 28.

“Fans can share their joy on the bridge, shake their hands and chant, ‘We made it!’” said Yoshimura during a news conference on June 27. “But please refrain from jumping up and down on the bridge.”

The alert was triggered by the uproar caused by about 500 exuberant fans who jolted the bridge when jumping for joy early on June 25 after Japan and Senegal played a tense match that resulted in a 2-2 draw in their Group H clash.

“Ebisubashi bridge boasts a safe and solid structure, but it was not built on the assumption that more than 500 people jump on it at the same time,” said Yoshimura.

According to the city’s construction bureau, the bridge measuring 26 meters long and up to 18 meters across was built in 1615 in the early Edo Period (1603-1867). It is designed to bear 190 tons and can support 2,500 people weighing 70 kilograms each.

Making a rough calculation of the load the bridge has to bear from a 20-centimeter-high jump, the bureau said it would be 1.5 times the weight of the individuals jumping.

"Passers-by could become injured by falling on the ground, for example,” said a bureau official.

The bridge is known as a spot for diving into the Dotonborigawa river for overjoyed fans of the Hanshin Tigers professional baseball team when it won the Central League pennant or the Japan Series.