A high-school freshman who committed suicide by running into the path of a tractor-trailer last week left behind a note that said he wanted to draw attention to the problem of bullying, his mother said Tuesday.

Fourteen-year-old Brandon Bitner complained about teasing and name-calling when he was in middle school, but after he entered Midd-West High School in Middleburg this year, he began concealing his pain from school officials and his family.

"He didn't want to burden other people with his problems," his mother, Tammy Simpson, said in a telephone interview as the family prepared for Wednesday's funeral in this rural central Pennsylvania community. "I'm sure he felt that, if somebody said something, (the teasing) would get even worse."

State police said Bitner walked several miles from his family's home in Mount Pleasant Mills before killing himself early Friday near Liverpool.

Simpson described her only son as a soft-spoken youth who aspired to be a classical violinist and had many female friends. His note said he was tired of being called names like "faggot" and "sissy," according to The Patriot-News in Harrisburg.

Simpson said her son "never told us" what his sexual orientation was but that she didn't care.

"He was the most wonderful child anyone could ask for," she said.

In his note, Bitner cited an encounter with another student in the school cafeteria several days before his death as "the straw that broke the camel's back," Simpson said.

The incident in question occurred Nov. 1, four days before his death, during a program that high-school principal Cynthia Hutchinson said is designed to promote positive behavior among students. Among other things, several students take turns wearing the costume of the school's mascot — a mustang — and roam around the cafeteria high-fiving, hugging and dancing with students during lunch periods, she said.

The young man wearing the costume "hugged a fair number of students throughout the cafeteria that day and Brandon was one of them, but that was all that happened. It was absolutely innocent," the principal said in a telephone interview.

Simpson, however, said her son thought he was being ridiculed.

The student in the mustang costume has a reputation of being "kindhearted and would never do anything to hurt or offend anyone else," Hutchinson said. "I can only guess that (Bitner) misunderstood and misinterpreted."

Wesley Knapp, the Midd-West School District superintendent, said the suicide prompted him to re-evaluate the safeguards that the school district has set up to prevent bullying.

"When you lose one of your students, it's painful," he said. "We all ask ourselves what could we have done perhaps to have prevented it."