@Rich Weese , when I was in second grade, we moved into a home where the previous occupant had taken apart and presumably rebuilt a car engine in one of the bedrooms. Engine oil doesn't come out of white carpet...

Same guy took a rototiller to the backyard. This was in Turlock, CA and there was an underground sprinkler system. We couldn't even go in the back yard until my dad went through and removed all the broken PVC pipes at odd angles sticking out of the ground everywhere. 

1) Three chihuahuas (not on the lease) were never walked for 6 months and used under the bed as a litter box. All the baking soda couldn't get the smell up from the hardwood floors.

2) Different unit. Tenant tells me I need to replace a window that broke. He noticed it was broken when he used it to break back into the house from locking himself out... 

Originally posted by @Kim Meredith Hampton :

@Mindy Jensen I think one of the worst, was when a tenant moved out, we went to do move out and turn the home, found a dead dog in a cardboard box in the garage.

During a routine inspection, on a tenant with no pets; a room full of spiders and snakes. Smelled to high heaven, and he didnt see anything wrong with this!!!!! really

We have had 4 people die, three of them in one year, but all were found relatively soon, so we didn't get the dead smell!!!! One hung himself, so not fun contacting the relatives

 Why didn't you let police make that phone call?

Inherited tenant with a dog that did not go on walks outside- instead the dog used pee pads and the backyard exclusively.  The pee pads which must have leaked because the hardwood floor was badly stained.  Also the yard constantly had poop in it despite many reminders to clean up after the dog.   They did not get a lease renewal.

@Account Closed the police did call someone, but it was not the person that we had as an emergency number on file from the tenant. In addition, we had to deal with his belongings, which police will not do. You must preserve their personal belongings and make sure that not just "anyone" come in and remove their items. Death in a rental property is something tthat must be handled with the knowledge of the laws about next of kin, trustee etc,,, 

So far the worst has been things like getting a dog without telling us, and parking on the lawn, or things like allowing others to stay over (we suspect subleasing, but no proof)... compared to others. .. wow. wow... maybe I don't have it bad... good luck topping @Deanna McCormick 's 3 dead bodies.. 

Love the stories.  Especially dead bodies.  

Two things come to mind.  Had a drug dealer with kids and dogs.  Apparently they left the kids to fend for themselves with the dogs.  It literally had 2 inches of hair and feces in every room, appliances gone, copper gone, grab bars, mirrors, door handles, and anything else you can take.... gone.  Kids drew on every wall etc etc. buried dolls in the yard and other weird stuff too.  Kept thinking I was going to find a body but never did.........yet

Second, was I rented a property to a single guy with good credit, no rental history.  This was when I was just getting started and dumb.  He was a really nice guy, clean cut, respectable looking etc.  He talked me down to only having him give me a 100 dollar deposit.  The place was one side of a duplex and only about 500 sq ft.  In the matter of 3 months, he had 7 other guys living with him.  I eventually told him that he had to leave after he violated every part of the lease imaginable.  Ruined the plumbing, holes in walls, smoking inside, completely annihilated the floors, etc.  Than he asked me for his security deposit back citing it was normal wear and tear.   Haha, I couldn't believe it.  Than he turned around and moved into one of my brothers rentals, and did the same thing, and another buddy of mine the same thing.  All in about a year time span. 

One tenant did the rotten meat in the fridge. Had to replace fridge.

One tenant left a deuce in the washer...

One of the more creative, was a tenant leaving a deuce in the toilet tank... I believe that is called an "upper decker". 

Had 2 deaths but were found quickly so no mess. My uncle had a suicide in his building that was pretty bad.

I've had almost all of the above over the years but the worst I heard of was a buddy of mine was renting out a garage to a tenant. It was one of those cash deals, $60/month, nothing serious. 

Well, needless to say, my friend has screened everyone since and put in place some safeguards in regards to accountability because the tenant loaded up the entire garage with asbestos. Literally cost thousands of dollars to clean it out. I'm talking floor to ceiling, full of what is essentially toxic waste. At the time I think it was at least $200-$300 per trashbag worth of asbestos to take out to the dump.

I also had an interesting spin on the car engine story. I once had a tenant take apart their whole engine in the front yard, pieces everywhere. The thing was...he couldn't figure out how to put it back together! Also it was dead of winter at the time, just to give you an idea how smart that guy is.

This is at a managed unit: Evicted tenant came back and torched the garage. Sounds bad, but we had been trying to figure out how to get rid of the garage anyways. Problem solved.