I've had something that seems to be the same a handful of times. Disconcerting. Though I once had something like this while I was lying awake in the early hour

I've had something that seems to be the same a handful of times. Disconcerting. Though I once had something like this while I was lying awake in the early hours of the morning, which was weird. It turned out that it was the Buncefield oil storage depot exploding about 40 miles away.