Earthquake? Frost Quake? What WAS That Anyway?

Last Thursday and Friday many residents in the vicinity of the 626 Flatbush demolition were freaked the eff out by what felt like a seismic event. I've heard from a number of people near the site that they experienced a crazy rattling of their houses that scared the bejesus out of them. From a neighbor all the way on the other side of Flatbush:

It actually happened on Thursday and Friday. The worst was on Thursday, the 6th. Just before noon there were loud booms sounds that shook the house. They sounded like they were coming from my roof. I would liken it to the sound of very close-by pile-driving. Or as if someone was banging (hard) against the side of the house. Literally, the roof was shaking and vibrating, the cabinet doors to my closet were rattling as did the windows. This went on repeatedly for at least an hour to an hour and a half. I thought that our roof joists were in structural failure and that I should perhaps evacuate my house. I did actually back up the important files I was working on, just in case.

These subsided for the rest of the afternoon until around 5pm when they started again for about a ½ hour. It was during this time that I was talking to my mother-in law who had just read a story it that day’s paper about these strange frost quakes that have been happening in various places around the Midwest and Ontario. It was an AP story that was picked up by many news organizations. The descriptions and weirdness seem to jive as well as the fact that they happen after a rapid dip in temperature. These booms happened again on Friday about 11:45 for about 15 minutes and around 2 pm for a few minutes. My next door neighbor was home on Friday and she felt them also.

Frost quakes? Y'all know what the heck happened? Did you experience this too? Was it related to demolition? And why is there now a Stop Work Order at 626? Please share any and all!