After close inspection, I observed that the quick release skewer snapped at the point where the fork rests on it. I think that the weight of the bike in combination with a hard front fork creates too much force on the skewer. I'm curious if these other cases also involved a broken skewer. You might have to inspect it closely if you were able to recover the skewer.

This happened to me recently. I was riding downhill on a paved street and a dip in the road caused the front fork to lift right off the wheel. I'm still in recovery after suffering broken bones in my right foot and a lacerated heel. I had to have screws and a plate installed in my foot and still can't walk over two months later. The hard fork is not safe without some kind of safety mechanism on the quick release. I contacted Rad Power Bikes to order a front suspension fork from the Rad Runner Plus but they told me it's not compatible with the Rad Runner. I'm not sure why it wouldn't be compatible based on the photos.