The head of FEMA’s Urban Search and Rescue branch, which runs a network of teams stationed across the country that can swiftly respond to natural disasters, resigned on Monday.

Ken Pagurek, a longtime Philadelphia firefighter who served as chief of FEMA’s search and rescue branch for the past year, was well-versed in major disaster response.

Ken Pagurek had become increasingly frustrated with the Trump administration’s efforts to dismantle the agency, CNN reported.