WARSAW (Reuters) – An explosion in a coking plant in southern Poland owned by miner JSW injured six people and caused a building to collapse, a fire brigade spokesman said on Thursday. The explosion at the Koksownia Przyjazn plant in Dabrowa Gornicza was reported to the fire brigade just before 1300 GMT, spokesman Stefan Flasza said. Flasza said that one building at the site had completely collapsed while another had partially collapsed. “At the moment there are 17 fire brigade units at the site,” he said. “As a result of the incident six people were injured. They are mainly people who have be…