A fire in industrial South Auckland is sending large plumes of black smoke into the air.  About 15 crews and fire trucks are at the site or on their way to the commercial building in Roscommon Road, Wiri.  Auckland’s Fire and Emergency is advising people in the area to avoid exposure to the smoke by shutting doors and windows, turning off air conditioning and staying indoors where possible.  A large fire is sending smoke into the air in South Auckland.  “A large plume of smoke is drifting over parts of South Auckland,” FENZ said.  Roscommon Road is closed.  A motorist in the area said traffic was gridlocked on streets around the fire with police diverting traffic back onto the motorway where possible.  Police said cordons were in place at the intersections with Wiri Station Road and Cavendish Drive.  “Fire and Emergency NZ continue to respond to the fire. Motorists should take alternative routes wherever possible and expect delays.”  A fire in an industrial area on Wiri's Roscommon Rd sent smoke across the city.  Witness John Day said he saw around eight fire engines rushing to the fire.  In video sent to the Herald, smoke pouring out of industrial building is seen filling up the sky while flames shoot out the side.  Parts of the building are seen falling to the ground as the blaze grows in the building.  Several businesses neighbour the site of the fire, including Z service station.  A staffer at another nearby business said, “No comment at this stage - everyone’s rushing around”.  More to come.