TUCSON, Ariz. -- Rep. Gabrielle Giffords led a crowd in the Pledge of Allegiance, her words ringing out across a cold Tucson night in a rare public appearance Sunday evening at a candlelight vigil one year after surviving a deadly shooting.

The Democratic congresswoman -- who has struggled to re-learn to walk after being shot in the head -- stepped onstage to cheers from the crowd. Ron Barber, a staffer who was wounded in the rampage that killed six one year ago, invited her to lead the audience in the pledge.

The crowd chanted, "Gabby, Gabby."

She limped to the podium, and husband Mark Kelly helped lift her hand over her heart. After months of intensive speech therapy, Giffords recited the pledge with the audience, head held high and a smile on her face as she punched each word.

The remembrance at the University of Arizona capped off a day of events, including a church service that drew hundreds in the afternoon and a citywide bell-ringing at 10:11 a.m., the exact time a gunman started shooting at a Safeway political event on Jan. 8, 2011.

With hugs and tears, southern Arizonans remembered the dead, the shattered lives and those who acted heroically after a gunman opened fire at an outdoor meet-and-greet.

"Even in the midst of this troubling year, the healing, the courage that we have experienced in our community -- each one of us can notice how our cups overflow with the blessings of our lives," said Stephanie Aaron, Giffords' rabbi, who recited the 23rd Psalm at an interfaith service at the cathedral Sunday afternoon.

Relatives of the six dead walked solemnly down the aisle with a single red rose, placing the flowers in a vase in front of a picture of a heart.

Suzi Hileman, who was shot three times, hugged Giffords and walked to the candle area. She lit one, put her hands over her heart and mouthed "thank you" to the crowd.

Hundreds of people at the cathedral -- including Gov. Jan Brewer -- stood and chanted, "We remember, we remember, we remember with grateful hearts." Some closed their eyes while others held each other.

President Barack Obama called Giffords on Sunday to offer his support and tell her he and the first lady are keeping her, the families of those killed and the whole Tucson community in their thoughts and prayers, according to the White House. He said Giffords is an inspiration to all Americans.