Concern is fine and dandy but knowing why the person feels unsafe is more important. Simply stating they feel unsafe means little and helps not at all.
1: Hi, 2, how's it going tonight?
2: I don't feel safe.
1: Why, did something happen?
2: No, but I heard about an incident involving 12 and a t-shirt.
1: Really? Let's find out what happened.
2: No, it makes me feel unsafe.
1: Shouldn't we know what actually happened before getting all worked up?
3: If 2 feels unsafe that should be good enough. This place isn't safe for even numbers!
1: But it's a rumour. We don't know what, if anything, happened.
5: Your a racist, disgusting, evenogynist CHUD!
4: Yeah! You want to rape all evens!
1: No, I just want to know what happened.
5: You ******* CHUD! Can't you see it is your privilege that prevents you from seeing? That's why you want to rape all evens and eat their children.
1: WTF?
4: See!
1: 2X WTF?
2: I can't be friends with you anymore, CHUD... oh! I mean 1.
5: Come on, lets leave this CHUD and start our own group. We'll call it Numbers+!
2, 3, 4: Yeah! [Leaving]
6: Hey, 1, what's happening?
1: Did you hear something about 12 and a t-shirt?
6: Yeah, 14 was wearing a t-shirt that said, "I like all numbers." 12 got upset because she felt it was making fun of her. Why?
1:

Any idea what a CHUD is?