Moment of Silence Observed Across the Country for Tucson Shootings

President Obama led the nation in a moment of silence today at 11 a.m. ET to honor those injured and killed in Saturday's mass shooting, which has left Arizona Rep. Gabrielle Giffords in critical condition.

The moment was marked across the country at the White House, the U.S. Capitol, the Arizona State Capitol, and elsewhere. Giffords' brother-in-law, astronaut Scott Kelly, led a moment of silence from aboard the International Space Station.

Six people were killed on Saturday after alleged gunman 22-year-old alleged gunman Jared Loughner open fired at a town hall-style meeting at a Tuscon grocery store on Saturday. Fourteen more were injured, including Giffords, who was shot in the head.

Below are some images from today's moment of silence.

Members of Congress and their staff observed the moment of silence from the steps of the Capitol. House Speaker John Boehner observed the moment of silence from Columbus, Ohio, where he was attending the swearing in of Gov. John Kasich.

U.S. Capitol guide Michael Judge; Theresa Nazario; Terri Womack, wife of Rep. Womack; Rep. Steve Womack (D-Ariz.); and Capitol guide Ara Carbonneau observe the moment of silence at 11:00 a.m. in the Rotunda of the U.S. Capitol. A memory book is available to sign today at the Cannon Rotunda.

American flags fly at half staff on the National Mall in front of the U.S. Capitol in memory of the victims of Saturday's mass shooting in Tucson.

Crime scene investigators pause during a national moment of silence at the site of Saturday's shooting in Tucson, Ariz.

A television monitor shows President Barack Obama and Michele Obama as he presides over a national moment of silence, while specialists on the trading floor of the New York Stock Exchange observe the occasion.