JACKSON TWP — Several experts and a specially trained dog could not determine the cause of the fire Aug. 12 that resulted in an estimated $2 million in damage to a warehouse and its contents on Route 68, near Route 528.

State police fire marshal Jeff Crede said the cause of the fire has been ruled undetermined. Firefighters could not enter the warehouse to attack interior flames because the roof had collapsed. The fire was left to burn itself out, causing extensive heat damage.