A slew of vulgar graffiti was discovered on the roof of Dickinson Avenue Elementary School Saturday.
In a letter to parents, the Northport-East Northport School superintendent says the graffiti contained swastikas, sexual images and racial slurs.
Custodial staff were called to clean it up.
The superintendent says the district is working with Suffolk police on the investigation, adding in his letter, "There is no tolerance for acts of racism, hate or vandalism within our district."