What happened to Holly and Jessica was terrible and very upsetting.
It's easy to get very concerned when you hear about bad things happening to children on the news or in the papers.
And while it's crucial to keep yourself safe, it's also important not to let these worries affect you too much.
It is good to remember that this type of incident is very rare.
If you are worried, you can always talk to an adult you trust, like parents, family and teachers, or even your friends.
A spokeswoman for Childline said: "Cases like this can be very frightening. They can talk to us about this. We welcome calls about current events.
"For instance, we had a lot of calls about the war. Kids can talk to us about anything at all. We know what's going to come out and we're up on it. If a child is scared, we'll ask them what they find scary. We'll ask them what they think will happen. We'll get through it.
"The counsellors are told about what's going on in the news, so they're prepared. We don't have a line on it, we just listen to the kids.
We have a very thorough training. We have to be able to talk about the untalkable."