The death toll at the Pukkelpop music festival in Belgium, hit by a sudden violent storm, has now risen to five, say local officials.
Staging collapsed, giant screens fell, tents were flattened and trees were uprooted, all in the space of minutes after the storm struck.
Dozens more people were hurt, several seriously.
Belgian Prime Minister Yves Leterme has sent his condolences to the families of the victims.
Reports say organisers have now decided to cancel the rest of the event.
"During the night, the fifth festival-goer died in hospital. I think that the organisation of Pukkelpop rightly took the courageous decision to stop the festival," Hasselt mayor Hilde Claes was quoted as saying on the website of De Standaard newspaper.
She said all the dead were Belgians, adding that 140 people were injured in the storm, 10 of them seriously.
Dr Pascal Vranckx, of the Jessa Hospital in Hasselt, added: "There are still three patients in critical condition fighting for their lives."
Festival organiser Chokri Mahassine said in a statement: "Pukkelpop is in deep mourning."
'End of the world'
About 60,000 people were believed to be at the event, one of Europe's largest outdoor festivals, when the storm hit. Headline acts this year were set to include Eminem, the Foo Fighters and the Ting Tings.
"The sky suddenly turned pitch black and we took shelter waiting for the rain," said festival-goer Catherine Blaise, according to Le Soir newspaper.
"Then suddenly, there was a downpour. The wind blew violently. There were hailstones bigger than a centimetre falling... Trees toppled over.
"It was unbelievable, the end of the world," she said.
Within 10 minutes, the storm had turned the festival site into a scene of mud and destruction, reports said.
More than 20 ambulances raced to and from the site near Hasselt, some 50 miles (80km) east of Brussels. Those with lighter injuries were being treated at a local sports complex.
Many festival-goers were inside tents which collapsed when the storm hit.
"It was mass panic," Laura Elegeert, 17, told AP news agency.
"People were trying to get out of this tent that collapsed by using their pocket knives and cutting holes in the fabric."
On Friday, mud-splattered young people, many shoeless, trudging down the avenue leading from the festival site to bus and train stations. Many had camped on the site overnight, in the vain hope that the festival would continue.
In a news conference on Friday, Mayor Claes said initial checks on emergency planning measures - which staff told AFP news agency included "checking trees for their resistance to high winds, and testing the drainage system" - left officials confident they had done everything that could be expected of them given such freak conditions.
Hasselt officials and festival organisers described Thursday's weather conditions as exceptional, and said weather forecasters in the area had not predicted a storm of that intensity.
It was the second consecutive year of tragedy for Pukkelpop. Last year, lead singer of the group Ou Est Le Swimming Pool, Charles Haddon, committed suicide at the event.
Five people were killed last week at a festival in the US state of Indiana, when a stage collapsed in high winds.