A portion of a factory hall at the Poldi steelworks in the Czech town of Kladno collapsed Saturday killing at least two persons, reports said, according to dpa. The hall tumbled shortly after 7:00 am CET (0500 GMT) of yet unknown causes, Mlada fronta Dnes reported on its web site. At least six people were buried in the rubble, the report said. The rescuers have so far pulled out two bodies from underneath the ruins and three seriously injured. According to the report, the collapse may have been caused by work going on to dismantle the hall.