Urban Search and Rescue Chief Ken Pagurek quit over a new policy that led to delays in FEMA's response to the flooding in Texas on July 4, sources said.

The Federal Emergency Management Agency’s acting leader has adamantly defended the federal government’s response to historic flooding in Texas earlier this month, saying lawmakers’ attacks on the agency’s actions were unwarranted.

The head of FEMA's Urban Search and Rescue branch, Ken Pagurek, resigned on Monday, multiple sources confirmed to ABC News.