Over 40 firefighters are working to control a blaze at the Salt River Landfill north of Mesa early Friday morning. The fire broke out overnight near the Beeline Highway and Gilbert Road. Salt River Fire Department Deputy Chief Kevin Makil says the landfill fire did spread to a structure, one of the recycling buildings nearby. Firefighters are working to hold the fire to just the one building before it spreads to any other structures. Makil expects firefighters to be battling the fire throughout day. He said a cause of the fire has yet to be determined. Makil added no injuries have been reported so far. The Beeline Highway was briefly closed overnight due to low visibility from the smoke from the landfill fire. It has since reopened. No further information was made available.