CONCORD — A two-word message spewing racial hatred pierced a wall of tolerance at Concord-Carlisle Regional High School this week.
The slur, which included a curse word and a racial epithet that disparages black people, was discovered Monday on a carrel in the school’s library, where poetry and the classics line bookshelves.
“Everybody was really upset about it,’’ said Britny Rabb, a senior who participates in the Metco program, which shuttles African-American and Latino students from Boston to schools in the suburbs. “I was mostly hurt that I go to a school where I am not welcomed.”
The incident prompted a strong rebuke from school administrators, who sent out e-mails to students and parents.
“This is not a school community that will ignore racism,’’ wrote principal Peter Badalament, who launched an investigation into the matter. “We all need to stand up to intolerance.”
Concord police said they too are investigating and that the person responsible could be charged with damaging school property. Law enforcement is also looking into whether it is a hate crime. The school said the culprit faces suspension.
“We are treating this as a serious incident,’’ said Concord police Sergeant Jack Kennedy.
The posting has confounded the Concord-Carlisle community. People said the slur does not reflect the overwhelming attitude of the towns, where residents respect all people regardless of their religion, gender, or skin color.
“This is not the norm in Concord,’’ said Ronni Olitsky, who cochairs the Concord-
Carlisle Human Rights Council. “We are all discussing it, and we are all concerned.”
A male student first saw the writing on the carrel around 10 a.m. Monday. Using his smartphone, he took pictures of the message, scrawled in reddish gooey candy. He then posted the photos on Facebook and Instagram, according to several students.
Students were outraged that anyone at their school could write a comment so inflammatory that it brought many of their peers to tears.
“At first I was really hurt, but it turned into anger mostly because I feel that we try so hard’’ to come to Concord to get the same opportunities, said Iraya Flynt, a 17-year-old Roxbury teenager who attends the school. “This basically was a smack in the face.”
School officials confronted the issue Wednesday during regular advisory sessions where students gather in small groups. The students were shown copies of the racially charged post and asked how they felt about it. They were also asked what they thought of the state of race relations at the school, Badalament said.
A student at one of the meetings said African-American students in his advisory group said the school is not as racially friendly as they would like it to be. Some white students then pointed out that the African-American students self-segregate by always sitting together at lunchtime. The black students responded that they have tried to sit at other tables, but felt unwelcome.
Another student said his group discussed the merits of installing surveillance cameras in the school. Regardless, he said, the school should have a no-tolerance policy.
“I think this happens a lot, but it just isn’t as public,’’ said 14-year-old freshman John Kacher. “It became so public that they had to address it.”
Badalament said that while the school does not have an explicit “no tolerance” policy, it will not stand for behavior that discriminates against any students.
Concord, a wealthy suburb 20 miles west of Boston, is known for its picturesque beauty chronicled by famous native son Henry David Thoreau. The town of 16,000 has more than 1,200 students enrolled in its massive high school, and roughly 6 percent attend through the Metropolitan Council for Educational Opportunity Inc. program.
Some students who make the daily one-hour trip by school bus said they have not always felt at ease there. Last year for example, a white Concord-Carlisle student appeared in school wearing a T-shirt with a Confederate flag. The student was suspended, said Badalament, but it still rattles some students.
Several female students said they have been called derogatory slurs. “It’s an ongoing situation,’’ said Danielle Gordon, 17, a senior who lives in Mattapan. But the latest incident, she said “stirred something in me . . . Enough is enough.”
Soleina Garcia, a 17-year-old from Dorchester, said she has been in the Concord school system since the sixth-grade and had never encountered any problems until high school, a transformative time for teenagers. “It became less welcoming,’’ she said.
Asia Council, also 17, who lives in Roslindale, said she is encouraged by the number of students of other races who have joined in speaking out against the incident.
The school said it plans to hold more meetings so that students of color can share their personal stories and what it is like for them to be minorities in a predominantly white school.
“We are all working together, not just our group, but . . . students’’ from Concord and Carlisle, said Council. “There are kids who are participating and actively trying to help.”