I'll be succinct. I'm afraid we're having a full structural failure. Over the past week, crack after crack has been appearing in our plaster and walls. I'm honestly concerned for our safety.
Our home was built in 1890 and is a two-story brick and mortar home, 3 bedrooms, 2 bathrooms, newer roof, and an unfinished basement (read: dirt floor, moisture barrier).
A huge crack appeared almost overnight in our bathroom on the ground floor, including diagonal cracks from each corner of the window frame; the crack goes up the seam of the corner of the wall and continues across the ceiling. This is an external, outside wall.
There is a crack in the plaster in our dining room that runs floor to ceiling (12' ceilings) all the way up the seam of the corner. It appeared suddenly.
There is a buckle in one of the walls, which was there when we bought the house in 2005; however, the plaster has cracked open within the past two weeks.
Cracks are rapidly appearing throughout the house at the corners of the windows and above doors.
The floor upstairs (original wood plank) feels sloped and the floorboards are quite flexible -- springy, almost.
On the exterior there are cracks (hairline - vertical) around the foundation. I can see hairline cracking running almost the full frame of a good-sized, curved window we have in our living room.
I know this is urgent, but I don't even know who or what kind of professional to call in this situation to get an evaluation/inspection done. What's going on? Is my house falling apart around me?
ETA: 02.04.12 Well, we had both our homeowner's insurance agent come by AND a hired structural engineer. Here's the verdict: The floor is sinking. It's fixable; the joists need to be either reinforced or replaced. The structural engineer (who did a 1000% more thorough and professional evaluation than the insurance adjuster, who called it "settling" and just said it wasn't covered by insurance. . . thanks for nothing, lady! ;) ) found evidence of a previous fire that went unnoticed by two inspectors. This obviously may have weakened the beams. So we'll be interviewing contractors and having the repairs made. While not ideal, it's a relief that the foundation isn't failing. The engineer who inspected the property pronounced it safe to inhabit -- we just need to attend to the joists as quickly as possible. Thank you all for your well wishes and helpful and thoughtful advice. :)
ETA 2: 09.28.13 I thought I would come by and update this post. Because we wanted to sell the house, we had to make a decision that was safety-conscious, structurally sound, and as affordable as possible. We opted to reinforce the joists and support beams with new steel beams; this cost approximately $5,000. Finding an honest, yet capable, contractor was extremely difficult -- we were quoted estimates of up to $35,000 (!!!!) to fix the damages. Basically, the house settled rather fast and unexpectedly, which caused the extensive cracking of the walls. While rare, this does sometimes happen, and we had had a very dry winter in 2011-2012. I'm pleased to say that after the joists and beams were reinforced, we were able to put it on the market. It was up for sale for only 48 hours before we got a full-price offer with no contingencies, and we closed on 09.20.13. Now it is someone else's money pit. ;)