Many of those who worked at Columbine High School when two students opened fire have transferred to other schools.
Overall, about 60 percent of the staff has left Columbine since the Colorado school became the site of the nation's deadliest school shooting.
Annual teacher turnover for the district as a whole was just 11 percent.
Eric Harris and Dylan Klebold opened fire at the school in April 1999. They killed 13 people and injured 23 others before committing suicide.
The school's choir director decided to stay at the school where he once was a student. "When your house burns down, you rebuild it," he said.