Southern Lehigh High School students have been subjected to classmates yelling gay slurs and the n-word in the halls, calling black students cotton pickers and using heil Hitler salutes.

Southern Lehigh High School in Upper Saucon Township is seen March 23, 2016. (Kurt Bresswein | For lehighvalleylive.com)

That's according to students and a letter high school Principal Christine Siegfried sent home to families following a special assembly on Wednesday, where the principal urged the study body to treat classmates with respect.

District Superintendent Kathleen Evison emphasized Friday that only a small number of students used the "extremely inappropriate language" and they have been disciplined.

"Our student body is an extremely supportive and collaborative student body," Evison said. "This is very unusual for us to hear this kind of language and, obviously, very disturbing."

High school junior Jamie Kish said he hasn't been a target of any of the name calling or harassment, but there's been a sharp uptick in such behavior this school year.

"It is noticeable and I do think it is a problem," Kish said. "I do think it is good the administration is trying to do something about it."

Siegfried came on the morning announcements recently to speak to students about reports of racial slurs, Kish said. The principal urged students to reach out if they needed someone to talk to or help understanding other cultures.

Kish took Wednesday's assembly as a sign that things had worsened and Siegfried felt she had to take a harder line with students.

"One incident is one too many," Evison said Friday. "To make sure we got ahead of this, the high school principal pulled students together and held an assembly to talk about respect, how everyone is different and this behavior will not be tolerated."

The message was well received by the student body, Evison and Kish said.

Lehighvalleylive.com asked Siegried on Thursday to provide a copy of the letter she sent home. The request was forwarded to Evison, who promised to provide it later Friday evening. By Monday afternoon, Evison still had not produced the letter.

The message sent home to families outlines the racially charged incidents and asks parents for their support modeling that this behavior is unacceptable, Evison said Friday, declining to get into the details of the actual incidents.

They include swastikas being carved into bathroom stalls, written on homework, laptops and screensavers, according to Kish and a copy of the letter obtained by The Morning Call and posted on the newspaper's website.

Students have been yelling the n-word in hallways at lunch and in gym. Black students have also been called cotton picker and lesbians referenced as "dykes."

"Black students seem to be one of the largest targets," Kish said."Some students think it is funny to yell slurs. It baffles me how people think this is OK."

The superintendent said she is not sure why students seem to think this behavior is suddenly acceptable. There's been no major changes at the school and this has not been an issue in the past, Evison.

"We are not a community that tolerates that kind of language and behavior," she said. "It is extremely disturbing and it needs to cease immediately."

Kish says it is hard to pinpoint why name calling and casual racism is suddenly acceptable behavior for some of his classmates. But he has to wonder the role the contentious and divisive 2016 presidential election is playing.

"I think that might be one of the reasons why students are being so loud and open with their opinions," Kish said, adding it's clearly not the sole cause.

He notes that Southern Lehigh is a middle class and largely white community -- 87 percent white, according to the Pennsylvania Department of Education.

"If you are a middle class, white teenager and you are growing up almost entirely around white, middle class teenagers, you won't get to experience how other people live," Kish said.

Siegfried's letter and speech during the assembly also touches on that idea. She reminded students they don't always know what a classmate is dealing with privately, some may not have enough to eat or a place to live or are dealing with struggles with friends.

"They need to be mindful of their words and their behaviors," Siegfried wrote. "Over the next several months we will be doing some school wide activities to continue to try and address some of these behaviors with our student body."

The district already builds awareness of diversity and cultural difference into its high school program, Evison said.

"We have many clubs that focus on that and this is an ongoing process," she said. "There are plans to have some more assemblies, guest speakers and continue to raise awareness."

Sara K. Satullo may be reached at ssatullo@njadvancemedia.com. Follow her on Twitter @sarasatullo and Facebook. Find lehighvalleylive.com on Facebook.