The Texas high school made famous in the book "Friday Night Lights" said Thursday that a longtime teacher committed suicide a day after being questioned about an alleged improper relationship with a student, the school's fifth former staffer to face such accusations in a little more than a year.

Mark Lampman taught government and coached girls golf at Permian High School in Odessa for 17 years. School officials did not detail his alleged relationship with a female student, but called it improper.

School district spokesman Mike Adkins says the school learned of the accusation Tuesday and that Lampman resigned after being questioned. School district police are continuing to investigate the student's allegation, he said.

Ector County Sheriff Mark Donaldson said the 47-year-old died Wednesday of a self-inflicted gunshot wound to the chest. A woman who answered the phone at Lampman's home declined comment.

Since spring 2013, five staffers have come under scrutiny for alleged improper relationships with students.

Adkins said the district provides training on the issue each year.

"If we knew why (these situations occur) we could address it directly and very quickly," he said. "It's as frustrating to us as it is for our community."

Two accused former staffers are awaiting trial, and police are investigating allegations against two others, Ector County District Attorney Bobby Bland said Thursday.

Bland said one accusation can lead to others.

"Oftentimes when somebody comes forward, other people will feel comfortable reporting, but I can't speak to these particular cases," he said.

In April 2013, Kathryn Maples, a former Permian history teacher who also coached swimming and diving, and April Collins, an athletic trainer at Permian, resigned. Two months later they were indicted on charges of having an improper relationship between an educator and a student, a second-degree felony punishable by up to 20 years in prison.

Trial dates for the women have not been set.

Maples was 28 when she was accused of having an improper relationship with a 17-year-old student. Collins, also 28 at the time of the investigation, was accused of having an improper relationship with a 19-year-old student.

Last week, a 25-year-old assistant softball coach at Permian who also taught physical education at a junior high, resigned amid investigation of a possible improper relationship with a Permian student.

In April, an employee at the school resigned after parents and students alleged to school district police that she was having a relationship with a student. The district declined to release her name.

Bland said he has not gotten case files for the two most recent cases.

Lampman, who was married with two children, was well-liked and respected by students and faculty alike, said Liz Faught, a substitute teacher at Permian. Several times Permian seniors had voted him their favorite teacher at the end of the year, she said.

But parents and colleagues are wondering about the spate of allegations over the past year.

"That's what the community has to be asking," Faught said. "What is this? What's this about? It's unacceptable."

Melisa Fowler, the mother of a Permian student, said there is sadness in the community about Lampman's suicide but the number of allegations is concerning.

"They're going to have to do something to help the situation," she said of district officials.

Permian's football program and its community support were chronicled in Buzz Bissinger's 1990 book, "Friday Night Lights." Director Peter Berg then made it into a movie. Years later there was a television show of the same name but it was about a fictional town and high school football program elsewhere in Texas.