Carrier/rack problems of the 2015 BMW X5

I was driving my BMW X5 on I-195 west bound in fall river MA. On Wednesday, July 17, 2019, driving at the posted speed limit in that section of highway. The roadway was lightly traveled, mid-morning. There were no overpasses or tunnels in this section of roadway. I suddenly heard a loud "booming" noise. The large, panoramic, main section of moonroof exploded, ripping away a significant section of glass, blowing out into the air and some imploded into mainly the right front seat and back seats of the SUV. I was the sole passenger and was not injured. At no time was there a loss of control. I pull over to the breakdown lane to review the damage to the moonroof and rest of the car. It appeared that the damage was contained to the center section of the moonroof. To prevent additional shards of glass from falling into the vehicle, I closed the internal shade of the moonroof, which has been open when the glass broke apart. I did not detect any external object hitting the vehicle and can only presume that the breakage was totally spontaneous. Also, while there is a BMW roof rack on the car, I was not carry any sports equipment at the time of the accident. There are two saddles on the rack for carrying a kayak. I did not contact any emergency or police. I have not seen a need to file an accident report with local authorities. I continued onward to an appointment at a nearby location outside of fall river and then returned home about an hour later. My reassessment of the damage when I got home was the same as the initial incident. I have been in contact with my insurance company and am awaiting a review by an adjuster. In the meantime, I have contacted my local BMW dealer to discuss the situation. For now, BMW has indicated that the damage is not covered. There are two photos showing a kayak. It is not on the car, but attached to a nearby wall in the garage of my condo.