Organizers of this year’s Roskilde Festival, which opens today (June 28), say they have improved security since nine fans were trampled to death June 30, 2001, while Pearl Jam was performing.

The victims – all men in their 20s from Australia, the Netherlands, Germany, Sweden andDenmark – slipped in mud in front of the festival’s main stage when some 50,000 fans surgedfoward. In all, 43 people were injured.

“We wish for the festival to recreate faith in safety and care,” said festival manager Leif Skov. The four-day event, now in its 31st year, is northern Europe’s largest. This year’s performers run the gamut from rock legends like Young and Bob Dylan, to younger chart-toppers including Robbie Williams, and Deftones.

This year’s eclectic assortment of artists also includes Basement Jaxx, Nick Cave, Beck, PJ Harvey, Wyclef Jean, Jurassic 5, Modest Mouse, Ozomatli, Placebo, Queens Of The Stone Age, Wynona, Burning Spear, The Hellacopters, and Stereo MC’s.

Nearly all 70,000 tickets have been sold for the outdoor event, modeled on the 1969 Woodstock Festival in upstate New York.

Police reviewed the new security measures and gave permission for the event to be held on a large field outside Roskilde, 25 miles west of Copenhagen.

“Considering what happened last year, the festival had to do something radical,” RoskildeDeputy Police Chief Bendt Rungstroem said.

No more than 60,000 fans will be allowed in front of the main stage, and they will be separated into groups by 4-foot-high fences with security guards in the corridors between.

The stage will be about a foot and a half higher than last year; if fans in back can see better, officials said, they may not try to push closer. Communication lines between security guards and the stage manager have also been streamlined.

Rungstroem said the measures are about as far as authorities can go. “If you tighten security too much, then a subculture will emerge,” he said. “Young people will start organizing concerts in parks without permission and that can be even more dangerous because there is no security.”