Three firefighters were killed and six others including two firefighters seriously injured today after a three-storeyed building collapsed in Gole Pulli area of Jammu city when they were trying to put out a blaze. <br />'' <br />'' The building housing a sawmill on the ground floor collapsed during fire fighting operations, trapping several people. <br />'' <br />'' The injured were rescued and shifted to the hospital. One of the firemen is being treated for serious burn injuries and the other is undergoing treatment for head injuries. <br />'' <br />'' A fire department official said they rushed firefighters after receiving a distress call at 4.48 AM and were making efforts to put out the blaze when suddenly the building collapsed at 5.30 AM. <br />'' <br />'' A team of National Disaster Response Force was mobilized from Pathankot and State Disaster Response Force has also joined the rescue operation.<br />''