I haven't seen the story picked up yet by any news source, but the vacated flour mill near downtown Longmont is on fire.
The whole area is closed off, and there is a white smoke cloud over the city. Coming back into town from the south around 10:15, you could see a big flame ball in the sky. The fire appears to be under control now (10:45 PM).
The flour mill from earlier last year:
It will certainly look different tomorrow, unfortunately.