The Fairfax County Fire and Rescue Department chief announced his retirement on Friday amid an investigation into sexual assault allegations in the department.

Fire Chief Richard Bowers' retirement will take effect April 30.

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This comes after a scathing resignation letter from the fire department’s top woman leader and problems that surfaced two years ago.

In April of 2016, firefighter Nicole Mittendorff hanged herself in the Shenandoah National Park after being shamed in sexually-explicit comments online by people who appeared to be fellow firefighters.

The county commissioned a report on the department's culture. It found 40% of firefighters reported experiencing or witnessing harassment, bullying and discrimination. Chief Richard Bowers vowed to make changes.

Last year, Bowers appointed Kathleen Stanley, one of only three women battalion chiefs in the department, to a new post called Women’s Program Officer. She told WUSA9 at the time that she was hopeful for change.

But, in January, Stanley resigned that post alleging the leadership "tolerates and often defends sexual harassment, retaliation and hostile work environment." The allegations prompted Nicole Mittendorff's husband, Steven Mittendorff, who is a Virginia State Trooper, to call for Chief Bowers to resign.

RELATED: Top woman leader in Fairfax Fire Dept. resigns in scathing letter to chief

Bowers was asked if he would resign, and he said no, defending his leadership. Then, the county board of supervisors appointed the county executive to investigate Kathleen Stanley’s allegations.

On Friday, Bowers announced his retirement. He was hired by Fairfax in 2013 at a salary $187,500.00.

“I hope this will allow Fairfax to grow and become the leader in the fire service. My only goal is to provide an environment where no employee feels they have to file a lawsuit to be heard and treated fairly,” Kathleen Stanley said in a statement.

Fairfax County released this statement:

Appointed chief in February 2013, Bowers previously served a 35-year tenure with the Montgomery County Fire and Rescue Service. During his time with Fairfax County, the department achieved a Class 1 ISO rating, which represents “superior property fire protection.” Bowers developed the department’s first strategic plan, oversaw fire station construction and renovation, and played a key role in the development of the new Public Safety Headquarters. Bowers has also worked to improve incident response times and strengthen relationships with the county’s other public safety agencies during his time as chief.

"Fairfax County has appreciated Chief Bowers’ outstanding record for community outreach and engagement. Under his leadership Fire and Rescue personnel spent tens of thousands of hours going door-to-door proactively offering residents help with smoke alarm inspections and safety tips,” says Board of Supervisors Chairman Sharon Bulova. “He headed our public safety team’s efforts during the World Police & Fire Games in 2015, earning accolades from participants and visitors from all over the world. With the chief’s enthusiastic hands-on support, charitable efforts like Fill-the-Boot for Muscular Dystrophy, jacket and backpack drives have helped the neediest of our community. The Board of Supervisors is committed to sustaining these positive efforts while ensuring a safe and positive work environment for all our brave men and women in uniform.”

Fairfax County’s Human Resources Department will begin a national search for Bowers’ replacement. County Executive Bryan Hill thanked Bowers for his service, and said the goal will be to ensure a seamless transition that allows the department’s lifesaving work to continue uninterrupted.

Efforts to address ongoing issues in the department related to leadership, bullying and harassment, conflict management, hiring and promotions and dedication will continue through the transition. “There is still much work to be done and addressing these issues remains a priority for the county,” Hill says. “The upcoming change in leadership will not impact our efforts.”

Hill said the county is focused on the future of the department and ensuring it remains the best of the best in terms of community safety, while continuing to improve department culture.