Could she possibly be opening it to get rid of the smell of.... something illegal going on? I personally would call the fire marshall's office and let them know what's going on. Don't worry about your super - either he does his job or he doesn't (and is quite able to take care of himself).

Thanks for the advice. When I've called the management office I haven't mentioned the cat specifically for that reason--why would they care about someones random anxiety? So I just mentioned the fire marshal sign and that it seems like a safety issue. I do hesitate to call the fire marshal even though I know there are regulations saying landlords can't penalize a tenant for calling. But we all know that there are ways of treating people poorly without being in violation of a rule/law.

Also, no it's not a security door so at least anyone coming into the hall have already gotten access to the building. (Though people do prop open the security door to outside a lot too.)

I had thought of the smell issue. I know people do prop open the doors periodically for awhile when they've cooked something potent which doesn't bother me since it for short times. But, this doesn't seem to be the case as I haven't smelled anything strong. The logic behind it is so confusing! It makes me think they're now doing it just because they know I'm closing it.

I think I'm going to give it a day or two to see of it continues and then try the letter if nothing gets better. At least today it stayed closed for several hours between when I closed it and when I drove by on my lunch break. And when I closed it after work they've yet to open it again--it's been 2 1/2 hours. So it's a step in the right direction. Maybe they finally got the letter and aren't being so vigilant about it...

Thanks again for the advice! I was afraid someone would immediately say I'm being unreasonable.

Oh, I don't think you're unreasonable at all. As a LL I cover myself as best I can from these kinds of situations (houses, tho). And the reason I suggested holding off on the FM is for just the reason you stated. Not knowing what type of LL you have, some could take it as a personal affront. But I still say if you get no results beyond a letter or two, FM is a viable alternative.

I'd be interested to know how it goes.

So WHAT HAPPENED? I have the same issues going on where I live and just typed up a letter listing building and fire code regulations. Curious what happened in your case?

It sounds like they are propping it open to let unauthorized people inside. Have you tried asking them why they prop it open? Is it locked from the outside so that you need a key to get in?

Cindy, it's very unlikely the OP will see this since the issue is over 6 years old.

Hmmm sounds like a typical high rise type situation. Yes, put all of this in writing-documenting every incident including times and dates if possible. Give a copy to management (keeping a copy of your own). If this doesn't get any results, then go to the fire marshal and let him know what is going on. Security in these buildings is so lax that people are letting people in off the street. They either are not thinking or they don't care that somebody might come in and rob and murder the residents there. That's a scary thought, but it can happen especially in a big city.

I have a pyrophobic and fumiphobia condition. Fear of fire and smoke in those orders. December 29, 2017 a woman was attending her 2 year old daughter in another part of the apartment when she heard her 4 year old screaming. She rushed to find out what was wrong with him. You guessed it. He had started a fire in the kitchen. She grabbed him and her daughter and fled the building . . . leaving the apartment door open. Toxic smoke rushed out of the apartment and up the open first floor fire door and chimneyed up the stairway to the open fire door on the fourth floor. EIGHT DEAD. Worse fire fatality in New York City in 25 years. I stay in a one bedroom apartment on the third floor of an apartment building. Once I tried to explain to my neighbor down the hall about keeping the doors closed do to fire safety. He went into a rage, said he didn't give a damn and stormed off. I'll never say anything to anybody else in that building about fire safety. Back to my phobias; I keep a strong rope tied to my radiator in my apartment so in case of fire I can repel out the window to the ground. I keep a flashlight, shoes, clothing, my wallet, credit cards, money, my cell phone and gloves in a hat by my bed. I never fall asleep while cooking. I have five WORKING smoke detectors in my apartment. Two by the apartment door, three in my bedroom. Smoke inhalation kills more people then fire. Good luck to all:)