Description: On the evening of Aug 2nd, 2015 at 23:40 hours PDT, I observed from my Northeast facing patio and across a small lake (Crocker) a very bright light with occasional flashing white/yellow light moving rapidly soundlessly across SE to NE. at approximately 50,000 feet. It moved in sudden increase (almost jerks). From my location looking SE we often see aircraft from/to Seattle Tacoma Airport. This was not normal aircraft behavior and unlike any satellite I have ever observed. It passed from sight and within one minute (approximately). In the NNE sky at a lower altitude occurred a brief streak of white light N to NE. Within an instant occurred a massive, but silent explosion. This was an enormous and lengthy increasing yellow/orange width and height (enormous) and flames had momentum from N to NE opposing the travel of the earlier sighting. I am a pilot of many years, ex US Air Force Survival Instructor and I have (SEA) experience (distant) SAM (Surface to Air Missiles) contacts. To my mind this was a SAM (type) attack against what earlier was an (UFO). But the strike was from a “Beam” not a missile. What I first observed may have been any of many types of moving night sky lights – of shapeless UFO’s, BUT what followed was an instantaneous bright-light-beam originating low to high, that struck and obviously destroyed something significant in the night sky. Unlike a SAM strike, the orange/red/yellow flame increased and moved higher and expansively across the sky for some long moment. From my vantage point I would guess the contact/explosion was over or very near (high) over the U.S Navy Whidbey Island Airbase. I have flown to and from the Navy Island area to my lake property many times and have bearings on location. (P.S. This was not a “weather balloon.” )