Eight years ago when I conducted research on street harassment for my master’s thesis, I attended a Street Harassment Summit in New York City organized by Girls for Gender Equity. During a breakout session, the women in the room, from various diverse backgrounds, took turns sharing a story.

While each story was moving and infuriating and I included several in my thesis, one woman’s story still stands out to me today. She shared this:

“Street harassment is a huge part of my day and it makes me very angry and I think it’s always tied in with my racial identity. The worst thing that happened to me lately was I was on my way to work at a new job and I was very happy, and this guy said something to me and I kept walking. Then he came up around me in my face and said, ‘You look just like Bin Laden’s sister.’

My mouth was closed, and I was like, why aren’t I responding? He continued to scream at me and I kept walking, and he said, ‘You should get home, women like you don’t work. Don’t your men keep you locked up? Oh that’s right, your men aren’t real men. I’ll show you what a real man is.’ And he proceeded to tell me the actions that real men do to their women.

People on the street were stopped and were staring at me but no one said anything.”

As terrible as every part of her experience was, I will never forget the pain and betrayal she voiced at the end: that no one said anything.

In the years since then, I have heard her hurt echoed in so many people’s stories who feel doubly traumatized by the lack of kindness or even simple acknowledgement from the people around them. The sentiments also appear in stories submitted to my blog Stop Street Harassment, including incidents in Denver, London, and the Bahamas.

Street harassment can be annoying and upsetting, but it can also trigger deeper concerns. A study released last year by researchers at the University of Mary Washington found that sexual harassment is often traumatizing for women, especially for those who have experienced sexual abuse. A 2014 national study on street harassment in the USA showed that it can be frightening; 69% of harassed women and 49% of men said they feared the harassment would escalate into something worse.

Feeling alone and as if there must be something wrong with you since no one around you is speaking up can add to these feelings of trauma and fear.

There are many reasons why people may not speak up when they see street harassment happening. They may not be sure it IS harassment. They may not know what to do. They may think someone else will intervene. They may fear for their own personal safety. Those are all legitimate concerns and organizations like Green Dot and government entities like New York Department of Health provide tools and trainings to walk people through them.

But as we commemorate World Kindness Day, in addition to the obvious request to be kind and NOT harass others, the plea that I have to bystanders is a simple one: Ask the person if she or he is okay.

I am not the first to say this, of course, and last year social worker and avid Twitter user Feminista Jones launched the hashtag #YouOkSis? to especially encourage persons of color to reach out to women of color who are being harassed to check in and possibly interrupt a street harassment situation. But it warrants repeating.

What I want to emphasize is that if you feel too unsafe or cannot react in time to interrupt harassment, you can still check in with the person after the harasser is gone or the harassment has stopped. Let the person know you saw what happened and that you understand it can be upsetting. Let them know what happened is not okay.

A woman named Sara recently penned an open letter to her street harasser, a man in a car who told her to “move her fat ass along” as she walked through a crosswalk. Included in her piece was this: “To the woman on the sidewalk who said, ‘that’s so rude’ and shook her head when he drove off, thank you. Your three simple words in solidarity were my saving grace and snap back to reality, that no one, not even myself, has the right to disrespect my body.”

After hearing so many stories about the devastation people felt when no one around them acknowledged what was happening or how much of a difference it made when someone did, whenever I overcame my shyness and began asking women I saw if they were okay.

The first time I did this was in 2011 in Florida. I was attending a conference and I was out on a run. As I approached a bus stop where a young woman was waiting alone, men in a car swerved over and it looked like they yelled at her. When I reached her, I stopped and asked, “Hey, were those men bothering you? Are you okay?” She said that the men had circled around and harassed her three times. I told her how sorry I was and offered to wait with her. The bus came around the corner then, so she said it was okay, she could get on the bus now. I told her about my website and told her to reach out if I could help.

The next time I did it I was in New York City at Penn Station. A woman and a man were walking toward me and he was gesturing and talking loudly and she looked very uncomfortable and like she was trying to inch away from him. As they approached, I said, looking directly at the woman, “Are you okay? Is he bothering you?” She thanked me and laughed and said he was her coworker and he was just messing around and being annoying but she was fine.

I felt a little foolish — and that’s a perfect example of not knowing if someone is a harasser or not – but I have no regrets about asking. What if she had needed help?

The third time I spoke out I was walking from my office in Washington, DC to the Metro and I could see that as a woman ahead of me passed by a man, he reached out to touch her and talk to her and she recoiled. By the time I caught up to her, he was gone, but I told her I saw what had happened and that I was sorry – she shouldn’t have to deal with that. I asked if she was okay. She gave me a quick yes and thank you before she hurried on to catch her bus.

Street harassment, especially the accumulation of it, can be so tiring. So upsetting. With the three kind words of “Are you okay” or “You ok sis?”, you can help lighten someone’s load just a bit and let them know they are not alone.