By Drew Bollea  When the fire department gets the call of a collapsed building, the Urban Search and Rescue Unit is deployed. They specialize in looking for and saving people stuck in unusual circumstances. The men and women who respond to situations like Thursday's building collapse call it an "uncontrolled environment." Their job is to determine what's wrong and get the situation under control. Destruction is what members of the USARs team are accustomed to, when they arrive at the scene."Its pretty nerve wracking in those first 10 to 15 minutes," said David Tallent, a Tactical Services Officer with the Chattanooga Fire Department.The unit has about 120 members covering 10 counties. Tallent says working on a collapsed building has its risks."The first thing we do is make sure we evacuate the adjacent structures," said Tallent, "we make sure we have all the utilities shut down to make sure we don't have any gas leaks or gas explosions."They also hose down debris to limit dust and look for any materials or liquids that could be dangerous to crews."We do check for hazardous materials, asbestos," said Tallent.For Tallent to get information on other possible threats, he relies on the owner of the building, Calvin Ball."We just try to answer questions they had," said Ball, "they've been great to work with all day."Once the ground area has been inspected and is determined safe to progress, whats left of the structure comes toppling down.Tallent says the most important factor for any special operation is the well being of the people involved. Ball agrees that the situation could have been worse."I think the tenants and myself are glad that no one got hurt," said Ball.The cause of the collapse has not been determined. Ball tells us that they don't have any immediate plans to rebuild the vacant building, but they are considering their options and could sell the lot in the future.