Fire crews responded to the scene, a transfer station at 1350 N. 34th St., at about 8:25 a.m. after receiving several 911 calls from residents who said they heard a loud blast.
When firefighters arrived on scene, they found no smoke or fire.
An investigation found that the explosion occurred inside the metal recycling building after someone had improperly disposed of a barbecue propane tank into the metal recycling bin. The propane tank exploded while a backhoe operator was compacting the recycled metals.
The explosion was contained inside the metal recycling building.
The force of the blast blew out the windows to an unoccupied transfer station truck in the vicinity, but the safety glass on the backhoe protected the backhoe operator from any flying debris.
The other workers in the yard were uninjured.