On a sunny day in Southport, a bad thing happened when a person with a knife went into a dance class for kids.
The class had fun activities like dancing, yoga, and making bracelets, but the person hurt some of the children.
Three little girls, Bebe, Elsie, and Alice, didn't get better after the scary event and went to heaven.
Lots of other kids and two grown-ups were also hurt, and everyone in Southport is feeling very sad.