A Zionville man was airlifted from near the scene of an explosion and fire last night, an incident under investigation of the Watauga Sheriff serious arm injury and burns in an explosion inside the residence, injuries serious enough that a landing zone was set up right on US 421for WINGS Air Rescue to airlift the man to the Johnson City Medical Center while his family followed to the Tennessee Hospital. Sheriff Len Hagaman said that investigators were working the scene late into the night to determine what led to the explosion, but he said that the initial look at the scene ruled out a meth lab as the cause.