U.S. Department of Transportation Secretary Elaine Chao speaks during a press conference on the One National Program Rule on…
FILE - U.S. Department of Transportation Secretary Elaine Chao speaks during a press conference at EPA headquarters in Washington, Sept. 19, 2019.

U.S. President Donald Trump’s transportation secretary, Elaine Chao, announced her resignation Thursday, the first Cabinet secretary to resign because of Wednesday’s deadly invasion of the U.S. Capitol by a mob of Trump supporters.

Chao, the wife of Senate Majority Leader Mitch McConnell, who is a close Trump political ally, said she was “deeply troubled” by Wednesday’s violence that was fueled by Trump’s rhetoric.

“Yesterday, our country experienced a traumatic and entirely avoidable event as supporters of the President stormed the Capitol building following a rally he addressed,” Chao said in a statement. “As I’m sure is the case with many of you, it has deeply troubled me in a way that I simply cannot set aside.”

FILE - Mick Mulvaney, then the White House Acting Chief of Staff, speaks during a press briefing at the White House in Washington, D.C., Oct. 17, 2019.

Late Thursday, Education Secretary Betsy DeVos became the second Cabinet member to resign a day after the violence at the Capitol. She blamed Trump for inflaming tensions.

“There is no mistaking the impact your rhetoric had on the situation, and it is the inflection point for me,” DeVos said in her resignation statement.

Chao and DeVos joined a growing list of resignations from the Trump administration after hundreds of Trump supporters broke into the Capitol as legislators were in the process of certifying Electoral College votes in the November election, formalizing President-elect Joe Biden’s win.

Former White House Chief of Staff Mick Mulvaney said earlier Thursday he also was resigning as special envoy to Northern Ireland and said other administration officials have considered stepping down.

“I can’t do it. I can’t stay,” Mulvaney said on CNBC. “Those who choose to stay, and I have talked with some of them, are choosing to stay because they’re worried the president might put someone worse in.”

The president had urged his supporters at a rally Wednesday morning to march on the building, asserting the election was stolen and saying, “You'll never take back our country with weakness. You have to show strength and you have to be strong."

Late Thursday, Trump issued a video, condemning his supporters’ actions as a “heinous attack on the United States Capitol,” saying he was “outraged by the violence, lawlessness and mayhem.”

Four people died in the chaos, according to the Metropolitan Police Department in Washington.

Mulvaney, also a former Office of Management and Budget director, said he informed Secretary of State Mike Pompeo of his resignation Wednesday night.

Shortly after Mulvaney’s announcement, the Commerce Department’s deputy assistant secretary for intelligence and security, John Costello, said the violence also prompted him to step down.

“Yesterday’s events were an unprecedented attack on the very core of our democracy – incited by a sitting President,” Costello said on Twitter. “The President has long disregarded and diminished the rule of law and the constitution. Yesterday, that culminated in violent sedition against the U.S. Congress for the purposes of overturning a legally recognized and valid election.”

A leading developer of Trump’s China policy, Matt Pottinger, announced his resignation on Wednesday. A senior administration official said Pottinger stepped down in response to Trump’s reaction to the mob of protesters at the Capitol.

National Security Advisor Robert O’Brien, Pottinger’s boss, asked Pottinger to remain in the position to facilitate the transition to the new Biden administration but the official said Pottinger had “completed those tasks.”

FILE - Stephanie Grisham listens as President Donald Trump speaks to reporters on the South Lawn of the White House in Washington, Nov. 8, 2019.

Melania Trump’s chief of staff, Stephanie Grisham, who earlier served as White House press secretary, was the first administration official to announce her resignation on Wednesday. Deputy press secretary Sarah Matthews stepped down shortly thereafter, followed by White House social secretary Rickie Niceta, according to a White House official.

Matthews said she was grateful to serve Trump but underscored she was also troubled by the deadly violence on Capitol Hill.

“I was honored to serve in the Trump administration and proud of the policies we enacted,” Matthews said in a statement. “As someone who worked in the halls of Congress I was deeply disturbed by what I saw today. I’ll be stepping down from my role, effective immediately. Our nation needs a peaceful transfer of power."

The growing numbers of resignations and criticisms from some of Trump’s closest political allies about his behavior amount to a clear reprimand of the president. More resignations could be announced in the coming days, sources say.

The White House did not immediately comment on the resignations.