(CNN) A school district outside Buffalo, New York, has delayed the start of online-only learning programs for grades 5-12 because of mass staff resignations and leaves of absence, the superintendent announced on Friday.
In a letter to families, Williamsville Central School District Superintendent Scott Martzloff said 90 staff members have taken a leave of absence due to Covid-19 and 111 staff members resigned.
Additionally, 2,361 students opted into online-only learning, including 1,375 middle and high school students, creating more than 80 virtual teacher vacancies, the letter reads.
Due to the reduction in staffing, school will be delayed until further notice for all students grades 5 through 12 in the online-only learning model, Martzloff said.
Once adequate staffing arrangements are made, the district will notify families of a new start date, Martzloff said in a video posted online.
Students in the hybrid instructional model or K-4 online-learning only will begin classes on September 8 as originally scheduled, according to the letter.
Students are not allowed to switch instructional models until after October 1, when they will be allowed to switch once, Martzloff said.
The school board announced in a letter Saturday that they were unaware of the change for remote learners, and were told on September 2 that was the school was ready to start school on September 8. The board will hold a special online meeting Sunday to discuss the matter further.
"We sincerely apologize to the families that are impacted by this last-minute decision and we will work with the District to ensure students in grades 5-12 who are in the remote online learning model can start their school year as soon as possible," the letter said.
The school district's website says it is the largest suburban school district in western New York with a projected 9,919 students enrolled in the 2020-21 school year.
CNN has reached out to the New York State Department of Education for comment.