Scott Pruitt, the administrator of the Environmental Protection Agency, resigned on Thursday in the face of ethics investigations.

President Trump announced the resignation in a tweet sent from Air Force One.  The president said that he “had accepted the resignation of Scott Pruitt.  Within the agency, Scott has done an outstanding job, and I will always be thankful to him for this.”

The president also said that Andrew Wheeler, currently the deputy administrator  at EPA,  will on Monday assume duties as the acting administrator of EPA.  “I have no doubt that Andy will continue on with our great and lasting EPA agenda.  We have made tremendous progress and the future of the EPA is very bright,” the president said.

Wheeler, an attorney,  previously spent a decade lobbying at the firm Faegre Baker Daniels Consulting, where he represented energy, coal and mining companies as well as a mixture of others with issues ranging from food to salvaging automobiles.  Wheeler previously served four years at EPA during George H.W. Bush and the Clinton administrations.

On Capitol Hill, Wheeler also worked for Senator James M. Inhofe (R-OK) as well as serving as staff director and chief counsel to the Senate Environmental and Public Works committee.

Pruitt, in his resignation letter cited “unrelenting attacks on me personally,” as one of the reasons for his departure.  Pruitt had been hailed by conservatives for his zealous deregulation, but he could not overcome a spate of questions about his alleged spending abuses, first-class travel, and too close relationships with lobbyists.

White House advisers, including Trump’s chief of staff, John F. Kelly, had implored the president to remove Pruitt.  It has been reported that ultimately the president grew disillusioned with Pruitt after the accusations of impropriety and ethical missteps over shadowed Pruitt’s policy achievements.

Pruitt is currently the subject of at lease 13 federal investigations.  A government watchdog agency concluded that he had broken the law with his purchase of a $43,000 secure telephone booth.  He was also under investigations for his 2017 lease of a bedroom in a condo linked to a Canadian energy company’s lobbying firm and for accusations that he demoted or sidelined EPA employees who questioned his actions.