Levittown, Pa., once lauded as the ideal suburb for model American citizens returning from World War II, has been shocked by an intrusion of gang fighting that has caused a high school senior class president to be banned from his own graduation for fear he would be shot dead by gang members.

This threat has been met with anger as residents shake their heads at the prospect of Tyrone Lewis, their star basketball player and commencement speaker, not being present to receive his diploma on Friday.

“It’s a shame such a good kid is being railroaded like this. They should let him go to the graduation,” Mr. Lewis’s mother, Marlene, who has threatened to sue the school district, told the Associated Press.

“It’s a terrible thing, and I am surprised no one knows how to handle it,” a Levittown resident and maintenance worker at St. Michael the Archangel School, Margaret Scully, told The New York Sun.

Still, the Levittown Police Department, which heard about the threat from credible sources, said it was the best way to ensure the safety of the community as thousands gather to honor the graduates of Harry S. Truman High School.

The acting principal, William Haws, and the substitute superintendent, Ellen Budman, sent a letter to parents on Monday informing them that two students – who were not named in the letter, but who are Mr. Lewis and Ahman Fralin – would not be allowed to attend graduation, and that the decision was made “reluctantly.”

Mr. Fralin received a shotgun wound while driving with Mr. Lewis earlier this year. Though residents have speculated that the shooting may have been related to a gang rivalry – Mr. Lewis’s sister Rachael testified against a reputed Trenton Bloods gang member in the murder trial of Anton Cofield, who was murdered in a drive-by shooting last August – the shooting may have been related to road rage brought on after Mr. Lewis hit another car.

The threats and shootings that preceded them reflect the true nature of Levittown rather than the sitcom-like, peaceful image it is often credited with, a professor of sociology at Shippensburg University in central Pennsylvania, Chad Kimmel, said. Mr. Kimmel wrote his doctoral dissertation on the history of Levittown and is involved in the ongoing Levittown Heritage project.

The image of Levittown as the ideal community “is wrong,” Mr. Kimmel said. “It is one built on propaganda in terms of selling it as the American dream.”

“It’s an American community, and no community is insulated from violence,” he said. Mr. Kimmel noted that Levittown’s first violent crime – the rape and murder of a baby sitter – occurred only two years after the town was founded in 1952, and said gangs were present in Levittown as early as the 1990s.

Mr. Kimmel, who teaches courses on juvenile delinquency and violence, said gang members are probably “youth that are still kind of disgusted by the opportunities that aren’t there for them.” He noted that Harry S. Truman High School is located in the Bristol Township, which from its inception has been the poorer part of Levittown. The average income and average property value has always been lower there, he said. “Bristol from day one has been the black sheep,” he said.

“What we are seeing manifest itself in Levittown [is] this kind of lack of opportunity,” Mr. Kimmel said. “There is lack in Levittown.”

But for others, the ideal image of the city that once advertised itself as the “the most perfectly planned community in America” has not been shattered.

“Levittown is a wonderful place to raise children,” Ms. Scully said. But she said, as Mr. Kimmel did, that Levittown was not immune to issues the rest of the nation faces.

“The morals are not there. The values are not there. And this is what we are faced with,” she said. She added that she, too, recognizes the disparities between the various areas of Levittown.

Others see the shooting and other violent incidents as having less to do with Levittown than nearby Trenton, N.J.

“Levittown is still Levittown,” a resident who maintains a Web site about the city, who asked that his name not be printed, said. “Trenton is like the Wild West. There’s gangs killing each other right and left,” he said, noting that much of his information comes from local newspapers such as the Bucks County Courier and the Trentonian. “It’s not like that over here,” he said.

“I think it goes in spots and [is] sporadic, like any other place,” a circulation clerk at the Levittown Regional Library, Caroline McCallum, said. “The problem that this concerns is coming over from Trenton. … In my opinion, we have not been touched that much,” she said.