Both headlights burned out tonight... Why?

[Green Monster]

It's dusk and I come out of a store about 15 minutes from home. I hop in my 72 Blazer and start driving down the road. About 2 minutes into the drive toward home I see a flash in that projected to the front of my Blazer from what I thought was behind me.

My wife asked, "What was that?"

I replied, "You saw that too? Must have been a strobe light from some ricer or strobe in a red light that we just drove under."

One minute later, another flash, but this time it is evident that it came from the front of my Blazer as the car in front of me moved from the left lane to the right lane in a hurry. Now I'm driving in darkness and can tell my headlights are gonzo. I hit the high beams switch on the floor and both lights flash and burn out immediately. Now I'm in total darkness. I pull over and check the parking lights. I have all parking lights and signals work fine. Interior and dash lights work too. Its getting dark in a hurry as the sun has already set. So I drive home with the parking lights on and follow any car I can get behind just so I can see where I'm going.

So, what happened there? The headlight switch was not warm, nor have I ever encountered it being warm. I have not messed anything electrical on this truck. I have owned it since 2003 and installed Sylvania SilverStar headlights in spring of 2004 without any issues since. I have never had both headlights blow at the same time, high beams too on any car I have owned.

Sound like a short or bad ground? I figure my fuse would have gone first. I don't know for sure though. What should I look for.