That was the text I received from one of our neighbors on Sunday morning.

Apparently, for the second week in a row, my neighbor has startled a woman who appeared to have been sleeping at the top of the stairs leading down to the basement of our apartment complex. As it was starting to seem like a repeated incident, she decided to ask around.

Within one day, I surveyed three or four other neighbors in the building and found anther neighbor who had also seen this mystery woman. She validated the first story in that this woman appears to have had many bags and blankets with her, as if to be sleeping in our apartment building at night.

In the middle of the day yesterday, my husband and I returned to our apartment unit to see the front door lock completely busted out of its socket. Anybody could walk into our apartment unit from the street. This would be disconcerting any way you strike it — and now that we knew we had a stranger in our midst, it seemed to be downright terrifying. By the way, this was the third time in three months that our front door lock hasn’t functioned properly.

I knew we all had to be extra vigilant. Last night when I got home late from a dinner, I ran into another neighbor walking his dog and alerted him about the suspicious activity. He agreed to search the basement with me (so I wouldn’t be alone). We didn’t see anyone.

Then this morning at 5:30 a.m., I received a text from that same neighbor: “I checked the basement like you said last night before I went to the gym this morning…and the woman was there sleeping! I woke her up and told her she had to leave. We have to do something about this.”

That was all the confirmation I needed: It was time to rally the troops. To be clear, while the existence of one seemingly innocuous woman sleeping on our steps did not appear to be the most menacing person, it was the fear of something greater that stopped me in my tracks. After all, if there’s one woman we know about who’s illegally squatting on our premises, who else could be gaining access to our building? What other unintended crimes are we allowing to take place in our building? What other threats are we exposing ourselves to?

I immediately fired off a string of texts to multiple people in our building as well as a neighbor in the building next door and got to work.

I realize now that it’s actually quite the anomaly for people on the same floor (let alone the same building) to have each other’s contact information. Lucky for me, I’ve spent the summer getting to know my apartment building pretty well. In the course of the morning, I got tenants from 4 out of 10 units to validate my claim and agree to co-sign a letter to the management company with me.

At the same time, I wrote a letter to the remaining tenants, explaining the severity of the vast security breach due to a broken door, urging everybody else to file a formal complaint. I left these under the door of every tenant. Then I shared our formal complaint letter via email to folks in our building as well as to our neighbor next door. We delivered it to our property management company at 10 a.m.

By noon, I received word that the front door lock had been replaced. Talk about quick action. It was the fastest turnaround time I’ve ever seen among our management company. This is how it’s done.

Something I’ve realized about New York City apartments is that landlords and property managers just assume their tenants don’t talk to each other. One person can file a complaint and not realize that it’s been filed multiple times before. One person can see something suspicious but just assume that it’s something that’s been happening all along. It’s only when people come together and corroborate their stories that the truth comes up.

While of course it’s sad to see a woman without a home seal herself into the basement unit of another apartment complex, it’s important to separate this ethical conundrum from the security risk of something greater.

It’s only through the power of collective community that we were able to flag, validate, and resolve this issue before it grew any worse.

If you see something, say something.