Duisburg , Germany ( CNN ) -- As Germany paused Saturday to honor those who died at a German music festival last week , the pastor leading a memorial service sought to comfort those who lost loved ones , telling them `` love is stronger than death . '' Pastor Nikolaus Schneider spoke at the memorial at the Salvator Church in Duisburg . The church was the center of observances in the northern German town . Thousands of people came for the service , which was intended to honor the 21 people who died and more than 500 people who were injured at the Love Parade music festival on July 24 . Schneider told mourners that they should not sacrifice their trust in God or their zest for life as even the `` the Love Parade became a dance of death . '' Hannelore Kraft , the prime minister of North Rhine-Westphalia , cried audibly during the service . She spoke at length afterwards , promising a full investigation into the incident . She also had a message for those who lost loved ones , telling them to `` open your hearts to those who want to give you comfort '' and assuring them `` you are not alone . '' The service was broadcast at 14 other churches in town and at the local soccer arena , where about 1,000 people turned out to watch . German Chancellor Angela Merkel and President Christian Wulff both cut short their holidays to be at the service . Duisburg Mayor Adolf Sauerland was not there , however , after reports he had received death threats for allowing the Love Parade festival to take place in the city . The day began with a candle procession from the scene of the tragedy to Salvator Church and the arena . The church can accommodate about 500 people , and the seats were reserved mainly for relatives of the victims . Joachim Mueller-Lange , the vicar responsible for emergency spiritual healing , said all the families of those killed had been invited , including some who live abroad . Some families did not attend because burials were being held Saturday , while others declined because they wished for something more private , he said . A remembrance ceremony was also held at the Duisburg synagogue . The fatal crush happened July 24 in an underpass between the main event site and an expansion area . Witnesses told CNN affiliate NTV that people pushed into the tunnel from both sides until it was dangerously overcrowded . People were crushed against the walls and one another , losing consciousness and creating panic . The Duisburg public prosecutor 's office said 511 were injured . Police cordoned off the underpass Saturday to prevent a similar scene among mourners who may go to pay their respects . Merkel has called for a thorough investigation into the incident and said she was `` horrified and saddened '' by the tragedy . Some 1.4 million people had shown up at the popular festival , which featured dozens of DJs spinning techno music for hours , Carsten Leub of NTV said . Organizers had expected only 700,000 to 800,000 attendees , so they opened an additional event site to accommodate more people . The numbers are disputed by police , who say the area can hold between 250,000 and 350,000 , and at no time was it filled to capacity . Witnesses told NTV that police were warned at least an hour before the incident that the underpass was becoming dangerously crowded . An additional entryway had been opened before the accident to relieve some of the pressure . Police are investigating the cause of the back-up in the underpass . CNN 's Diana Magnay contributed to this report .
' : Festival of ` ` a dance of death , '' pastor says . Memorial service comes a week after a performance at a German music festival . German Chancellor Angela Merkel and President Walter Wulff attended the service . Others watched the performance in church and at a local soccer arena .