DUISBURG, Germany – Germany is holding a memorial service today for the victims of the Love Parade techno music festival, where 21 people were crushed to death and 500 injured.

The memorial is to be held at Salvator Church and shown live on screens in a football stadium and a dozen other churches in the western city of Duisburg.

Chancellor Angela Merkel and President Christian Wulff were planning to attend the event.

“We are expecting thousands of visitors,” said Achim Blaettermann, a police spokesman. “This is going to be a very emotional operation for the police, too.”

Ahead of the service, a group of rescue workers who had helped save victims during the mass panic at last weekend’s Love Parade carried a big candle into Salavator Church.

Anger had been building in recent days, with over 250 people protesting in Duisburg on Thursday and demanding the resignation of the city’s mayor, Adolf Sauerland.

People blame Sauerland and the city’s authorities for failing to adequately plan for the event. Private organizers also have come under fire for allegedly trying to squeeze as many as 1.4 million revelers into too small a space and for allowing only one access point onto the festival grounds.

A preliminary report by police investigators Wednesday accused the organizer of the Love Parade of major security breaches which may have led to the crush. But it left many unanswered questions regarding the responsibility of the Duisburg municipality, which was to oversee the event.

The crush occurred in a jam-packed tunnel that was the sole entrance to the festival grounds.

Since the tragedy, hundreds of people have lit candles, left notes and placed flowers on the site of the deaths and injuries.