It flew right over me here in California, but unfortunately I wasn't looking out the window and didn't notice it.
From the photos, it looks like something entering the atmosphere and burning up. A large meteor or a bolide. I've seen them before and they can be pretty spectacular.
It was traveling on a very flat trajectory, almost parallel to the earth's surface, which makes me suspect a satellite or other space-junk in a decaying orbit. But reports seem to have it traveling from east to west and I'd expect a re-entering satellite to be moving west to east.
So I'm guessing it was space-junk of the more natural sort: a large rock.
(Sorry, MR.)