WASHINGTON — A somber President Barack Obama led a moment of silence this morning for a nation stunned by an attempted assassination against an Arizona congresswoman that left her seriously wounded, several other injured and six people dead.

On a frigid morning, the president and first lady Michelle Obama walked out of the White House to the sounding of a bell at 11 a.m. They stood on the South Lawn, each with their hands clasped, heads bowed and eyes closed.

After a minute of silence, they walked inside.

The moment was marked on the steps of the U.S. Capitol and around the nation on the direction of the president, who called for the country to come together in prayer or reflection for those killed and those fighting to recover.

In total, 19 people were shot in the shooting rampage in Tuscon, Ariz. on Saturday. Democratic Rep. Gabrielle Giffords was shot point-blank in the head, and she remains in intensive care.

In Pennsylvania, Gov. Ed Rendell is ordering that all national and state flags in Pennsylvania be flown at half-staff in honor of the victims of the mass shooting in Arizona.

Rendell says flags should remain at half-staff through sunset on Friday.

By The Associated Press