(CNN) -- William Ruckelshaus, a key figure in the Watergate scandal and the first head of the Environmental Protection Agency, died in his sleep Wednesday, his daughter, Mary Ruckelshaus, told CNN.
EPA Administrator Andrew Wheeler reacted to the news, saying in a statement, "The entire EPA family mourns the loss," and calling Ruckelshaus the "father of the EPA."
"Thanks to his leadership, all Americans are living with better air quality, water quality, and a cleaner and healthier environment," Wheeler said. "I am grateful for his service to the agency. My thoughts and prayers are with his family and loved ones during this time of grief."
The New York Times was first to report Ruckelshaus' death. He was 87.
Ruckelshaus started at the EPA during the agency's inception in 1970. As administrator, he guided the EPA through the enactment of the first federal environment statutes, steps that would define the agency's place within the federal government.
Still, Ruckelshaus is perhaps best known for his role in the Watergate scandal and the Saturday Night Massacre of 1973. While serving as deputy attorney general, Ruckelshaus, along with Attorney General Elliot Richardson, refused to carry out President Richard Nixon's orders to fire special prosecutor Archibald Cox, who was investigating the scandal that ultimately forced Nixon from office.
"Nixon discharges Cox for Defiance; Abolishes Watergate Task Force; Richardson and Ruckelshaus Out," read the headlines of The New York Times at the time.
While he served under a Republican president in his role at the EPA, Ruckelshaus had shown support for Democratic candidates in more recent years, citing his concerns about the environment.
In 2016, he endorsed Hillary Clinton and assailed then-candidate Donald Trump, in a joint statement with William K. Reilly, who was the administrator of the EPA under President George H.W. Bush.
"That Trump would call climate change a hoax -- the singular health and environmental threat to the world today -- flies in the face of overwhelming international science," the duo said.
"For us, there is simply no choice in this election," Ruckelshaus and Reilly add. "We Republicans should be shocked, outraged even, at the prospect that all this progress, this legacy will be repudiated and rolled back by Donald Trump."
This story has been updated.
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