Ghosts in school

I am Gabriel Johnson, I am 19 years old. Ten years ago, a murder occurred inside our school and 10 children were killed. After this crime, the school guard said that he heard the scary sound of children screaming from the school at night, and not only that he heard the sound of people going up the stairs and when he went to check it He finds nothing and quit after one year, and after I graduated from elementary school, this school was closed.