Safe to leave oven on at 180F while at work to cook ribs? I'm currently at work and I'm having a little panic attack.

I followed a recipe that require the ribs to be wrapped in foil and cooked at 180F for 9hours.  I left about 30 minutes ago and for who knows why I didn't think it could be a bad idea before, but now I'm feeling unsure and worried.

The ribs are wrapped in two layers of aluminium sitting on a baking sheet.  The ribs were coated since last night in a dry rub and I've added sauce on them this morning before closing the wrapping again.

Please give me your thought.

Edit: I just wanted to give you guys an update.  So by precaution I asked my boss if I could take the rest of the day off and he agreed to let me go around noon (4+ hours into cooking), a risk I had to live with.

When I got home, my house was still standing in one piece and when I opened the door the smell running through my nose was incredible. I left the ribs to cook in the oven for another 5 hours before attempting to put them on the grill of the BBQ at high setting.

The ribs were a bit too tender so I lost some in the process of grilling them, but the taste was amazing.  It's the first time I manage to cook rib without boiling them first and I can honestly say I'm satisfied with the result, though I would probably cut down on the last hour in the oven.

As for the safety of this adventure, I think it would be safe to redo it unattended especially because of how low temperature is set, but as other people mentioned it is important to have a clean oven.

Happy safe cooking everyone.

EDIT 2: I have an electric oven.
Yes, there's a risk, but it's not significantly higher than having most other home appliances turned on  (eg, a lamp, dehumidifier, dish washer or dryer).

Although it heats up, a full-sized oven is insulated, and you're not operating at a very high temperature.  Provided it seals well, even if there's a fire, there would be little oxygen to sustain it.  I would not trust a toaster oven or desktop oven. with this sort of thing, as they're not as well insulated, nor do they tend to seal well.

As ovens are based on temperature, and will cycle on an off, rather than just feed in a constant amount of power (such as a cook top) ... so it won't get so hot that it causes other issues.

Update: I made the (possibly incorrect) assumption that this was an electric oven.  I don't know that I'd trust a gas oven the same way (as I would assume that it is not well sealed) ... although people leave their home heating systems and water heaters on without shutting them off when they leave each day, so it's probably not an issue.