Last night's Monsters of Rock festival was washed out by a violent fifteen-minute wind and hail storm that also disrupted the 2008 international exhibition cultural programme.
One spectator was hospitalised after being hit by a metal scaffolding plank, but was not seriously injured.
Around 7,000 heavy metal fans had been looking forward to a star-studded line-up, including the likes of Deep Purple, Thin Lizzy and Twisted Sister.
Organisers are assessing whether tonight's concerts, including a performance by Iron Maiden, can be salvaged.
At the Expo site, the storm, which struck at around 10pm, forced the suspension of a joint concert by Estrella Morente and Dulce Pontes, also interrupting the Iceberg show.
