St. Louis Park's school superintendent resigned suddenly this week, effective Friday.

School board Chair Anne Casey said during a board meeting Tuesday that she received a letter of resignation from Superintendent Astein Osei before the meeting. The board voted unanimously to accept Osei's resignation.

Casey read a statement, later sent to school families, saying the sudden change in leadership would not rock the district.

"I want to assure the St. Louis Park Public Schools staff, families, students and community that we all remain committed to a successful school year," Casey said. "We have exceptional leaders, highly skilled educators and an all around phenomenal staff who will continue to prioritize our students and families each day."

Osei's resignation comes just after his annual evaluation, conducted during a closed school board meeting Aug. 8.

State law requires the evaluations be held out of public view unless the superintendent makes the unheard-of move to request a public session.

School board Vice Chair C. Colin Cox said Osei had an unusual request for his evaluation in August: He wanted to be evaluated not only on how he had led the district, but also on his progress toward the goals the school board outlined in its plan for "racial equity transformation," Cox said during an Aug. 8 board meeting.

Casey said at the same meeting that the board would present a public summary of Osei's evaluation at its Sept. 12 meeting.

Osei did not attend the Tuesday meeting. His seat was taken by Tami Reynolds, director of student services, who accepted the role of acting superintendent.

Casey said the school board will start talking this month about the appointment of an interim superintendent, who would have more legal authority than an acting superintendent, and about the search process for a permanent leader.

"Through the transition of leadership in our district, we will continue to center students and stay focused on the day to day operations that make our schools exceptional places for learning," Casey's message to school families read. "Thank you for your family's continued momentum for a great school year."

Osei had been an assistant superintendent for Osseo Area Schools when he was tapped to lead the St. Louis Park district in the spring of 2017.