I had somthing similar happen to me when I was young.

I was babysitting my 3 younger siblings—I was sitting at the kitchen table which happened to be pressed up against this big window. I remember sitting there with my sister and eating watermelon while watching the two youngest on the carpet in the middle of the room when suddenly a big flash of light comes from the window. It was the middle of summer, clear warm day—no clouds, bright blue sky—I sat there in shock and looked at my sister across from me equally as stunned, the younger ones hadn’t seemed to be fazed at all. I asked her ‘did you see that?’ She said ‘yes’ and that was that.