I don't think it is a glass issue. Ford says it is an internal short in the electrical grid which makes more sense since it actually melts the back of the window frame.

Additionally, with the very hot temperatures reached, any glass will shatter at that point.

 

I told my wife the defroster switch didn't light up this morning as we were going down the road. Oh well, have had lots of electrical problems with this 2011 F150 SC since we bought it new.
So we ran a few errands, and were headed back home, about 40 mph in traffic, and I decided to try it again, to see if it "fixed itself." Nope, still not working. Five minutes later BOOM! Like someone said, sounded like someone touched off a 38 in the back seat! Couldn't figure out what had happened at first, even ran through the carwash to see if I could see any damage. Nothing external at all. Then back on the road I noticed that the passenger side panel of the sliding rear window is completely crazed (no holes) -- spiderwebbed across the whole thing!
I see others have had same. Dealer to look at it in a couple of days.
With this on top of all the other electrical problems we've had with this truck I might just be puttin on a bow tie!

 

I keep my 5 month old back there as well so this was a concern for me too, I now have "security tint" to help keep the glass in place if this does happen. 3M makes great security tint.

 

I had the same concerns, as we have grandkids too. Mine just crazed, and no loose glass yet. I can, however, feel the crackling on the OUTSIDE of the window, if I just very lightly run my fingers over it.

 

Our window exploded last week. Our Grandchildren were in the back seat when a LOUD blast shattered the window in a million pieces. It was so loud that one of the boys lost his hearing for about 10 minutes. I turned on the rear defrost about 5 minutes before the time of break.

 

Make sure to report this defect to the NHTSA so we can get a recall on it. here's the link.
https://www-odi.nhtsa.dot.gov/Vehicl...nt/index.xhtml

 

Ford should do a recall on this.

 

They should recall a lot of things but they don't unless they absolutely have to for safety reasons.

 

Better yet, design it right in the first place.

 

Not sure what to think about our 2011. Insurance replaced it -- just over $500 for the whole window, and I have the old one for a souvenir. I've used the defroster sparingly on it, but after reading about grandkids and hearing loss, etc, I don't want to take a chance on it. A recall, with a real fix, would be great!
May end up disabling the thing, and just using the mirror defrosters on that circuit like I read from another poster.