NEW YORK CITY -- A 12-year-old boy harassed by school bullies about his intelligence, his height and his deceased father killed himself in the New York City apartment he shared with his mother, according to relatives and those who knew him, NBCNewYork.com reported.

"I want to remember him as a happy kid," his anguished sister told NBC 4 New York on Thursday.

Joel Morales, of East Harlem, moved to a different school after enduring incessant taunting for months, but the bullying persisted, the fifth-grader’s family said.

Kids chased Morales, threw sticks and pipes at him and teased him for his smarts and his 4-foot-9 stature, his family said.

Morales’ anguish reached a breaking point when bullies taunted him about his father, who died when he was four years old, according to relatives.

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His mother, Lisbeth Babilonia, found him hanging in their apartment at about 11:30 p.m. Tuesday, hours after she had organized a search party when he didn’t return home on time from an after-school club.

An occupational therapist who worked with Morales at one of the schools because of his diminutive size told NBC 4 New York the boy only reluctantly talked about his problems.

"It was very difficult, especially with a child like Joel who wants so badly to please everyone, to see that he was really in pain, that he was struggling," said Maria Ubiles.

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Arlene Gago, a youth minister from a church group, said she spoke with Morales regularly at the Jefferson Houses where he lived but never knew of his distress.

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"I always asked him, 'How you doing? How's school?'" she said. "We talked but he'd never tell me what was going on."

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A classmate told Morales’ family that the boy had said he was tired of the bullying and told them the details of the remark about his father that sent him over the edge.

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School officials declined to comment on the alleged bullying, citing privacy issues.

Police said Morales left no suicide note.

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