MADRID — An ocean boardwalk collapsed during a nighttime concert in the Spanish city of Vigo, injuring 313 people, five of them seriously, authorities said Monday.

Many young people were on the port’s wooden boardwalk when it gave way around midnight Sunday at the closing event of a three-day festival, officials in the northwestern port city said.

Wooden boards cracked along a central section, about 130 feet long, and people slid down into the sea below, emergency services said.

Jesus Vazquez Almuina, head of the health authority in the northern region of Galicia, told Antena 3 television that 313 people required treatment. The five people who were seriously hurt did not have life-threatening injuries, officials said.

The president of the Vigo port authority, Enrique Cesar Lopez Veiga, said he suspects there was a structural problem in the boardwalk, which is supported by concrete pillars.

Associated Press