KATOWICE, Poland (AP) – Rescuers searched in bitter cold yesterday for victims buried when the roof of an exhibition hall in southern Poland collapsed on a racing pigeon show, killing at least 66 people and injuring 160.

The death toll rose steadily early yesterday as rescuers dug through the debris of the building, which collapsed at around 5:30 pm Saturday in the city of Katowice.

Tadeusz Dlugosz was dragged out of the twisted wreckage of the building, only to find out his 26-year-old son, who had been visiting another exhibit when the hall roof collapsed, had been killed.

People who escaped said two emergency exits were open, but other exits were locked, leaving others trapped.

Witness Franciszek Kowal, who got out onto a terrace and jumped about four metres (13 feet) to safety, saw people struggling to break windows to escape.

Attorney Grzegorz Slyszyk, who represents the company that owns the building, said he had no immediate information on the reports but that if exits were locked, the reason why would be investigated.

The hopes of finding survivors faded early yesterday after no one had been found alive since 10:00 pm Saturday in minus 17 C (1 F) cold, and crews who had been using only hand tools to pick through the wreckage were preparing to step up the operation.

Polish Prime Minister Kazimierz Marcinkiewicz joined several thousand others packing Katowice’s Cathedral of Christ the King on Sunday morning for a special mass being celebrated by Archbishop Damian Zimon for the victims of the tragedy.

Up to 500 people were in the exhibition centre on Saturday when the roof fell in. People trapped in the wreckage used cell phones to call relatives or emergency services and tell them where they were.

Crumpled birdcages were scattered inside the building near the entrance, and dozens of white and brown pigeons perched on the twisted rafters, their feathers ruffled against the cold.

Police said snow caused the roof to collapse, but Slyszyk, the attorney for building management disputed that, saying snow had been regularly removed and that it was too early to speculate on a cause.

Some 1,300 firefighters, police officers and mine rescue workers from around the region were brought in to help.

Prime Minister Kazimierz Marcinkiewicz flew in by helicopter and spent about 15 minutes looking over the site with rescue crews.

The 10,000 square-metre (110,000 square-foot) hall in the Bytkow district of the city had been hosting the exhibition, which opened Friday.

The “Pigeon 2006” fair was made up of more than 120 exhibitors, including groups from Belgium, The Netherlands, Germany, Ukraine and Poland, according to the fair’s Web site.

The gathering was devoted to pigeon racing, a sport in which homing pigeons are released and race home using their sharp sense of direction.

Katowice, some 300 kilometres (200 miles) south of Warsaw in a mining region, has been hit with the same heavy snow this winter that has been plaguing much of eastern and central Europe.