Witnesses reported scenes of panic after the packed platform buckled while a rap artist was performing, causing some people to fall into the sea.
The performer, Rels B, had told the crowd to jump just before the freak accident occurred, according to local reports.
"There were loads, I mean loads of people" on the boardwalk, one witness told RTVE.
One video posted on social media shows the perspective of an audience member filming the performance before the screen suddenly goes black.
At least 266 people, many of them teenagers, are said to have been injured in Sunday night’s incident during the O Marisquiño festival in the city of Vigo, north-west Spain.
Divers were deployed as a desperate search ensued however there have been no reports of any fatalities.
The original article was published in standard.co.uk.
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