Many were quick to notice Michelle Obama's absence on Inauguration Day, but the former first lady had a message to share on social media as questions over why didn't attend swirl.

As Barack, 63, Bill, 78, and Hillary, 77, entered the U.S. Capitol rotunda in Washington, D.C., on Monday for the 78-year-old’s historic swearing-in ceremony, people at the Capitol One Arena could be heard loudly booing.

Former President Barack Obama was spotted at the inauguration of Donald Trump. See pictures of the former president here.

Former first lady Michelle Obama will not attend the inauguration of President-elect Trump on Monday, the second time in two weeks that she will be absent from a significant event.

As Obama, Clinton, and Hillary, entered the US Capitol rotunda in Washington, D.C., for Trump’s historic swearing-in ceremony on Monday, loud boos echoed from the crowd at the Capitol One Arena

Bill Clinton will attend Trump's swearing-in ceremony ... Bush said he and former first lady Laura Bush are also attending. Michelle Obama was the only spouse absent at last week's funeral ...

Along with former First Lady Michelle Obama, former House Speaker Nancy Pelosi will not attend Donald Trump's second inauguration on Monday. Published reports indicate that Chinese President Xi Jinping will send an envoy in his place, and that Hungarian Prime Minister Viktor Orban plans on skipping Trump's second inauguration.

A spokesperson for Pelosi, who attended Trump’s 2017 inauguration, did not provide an explanation for the move.

The inauguration was the second gathering of U.S. presidents and their spouses that Michelle Obama has missed in recent weeks.

The crowded dais in the Capitol Rotunda on Inauguration Day featured four of the world’s five wealthiest men, five U.S. presidents, tech titans and business moguls, and two foreign leaders with

The men who held the nation’s highest office before President Trump have all remained mum on his taking the presidency on Monday.