TUCSON, Ariz. — Gabrielle Giffords marked the third anniversary of being shot in the head at a Tucson political rally by skydiving on Wednesday, part of a stunning recovery that has included learning to walk and talk again and founding a national organization that pushes gun control measures.

Across the city, others gathered for bell-ringing and flag-raising ceremonies to remember the six killed and 13 injured, including Giffords, on Jan. 8, 2011, as the former Arizona congresswoman met with constituents outside a grocery store.

Giffords waved and blew kisses to a crowd at a skydiving site between Phoenix and Tucson after successfully landing without injury.

“Gabby landed beautifully. Happy she’s safe. So proud of her bravery,” Giffords’ husband, former astronaut Mark Kelly, wrote on his Twitter account after the tandem jump with his wife strapped to a professional skydiver.

Jimmy Hatch, a former Navy SEAL who accompanied Giffords along with others, said the group held hands and formed a circle shortly after exiting the aircraft then made a line with Giffords in the middle.

“She was the least nervous person on the plane,” Hatch said, calling Giffords a “rock star” for making the jump on such an emotional day.

“They did a little moment of silence at the drop zone,” he said. “The emotion was really heavy. Then she smiled and said, ‘Let’s go.”’

Vice President Joe Biden’s office said he called Giffords on Wednesday to wish her good luck.

“Gabby’s courage & determination has been absolutely inspirational,” Biden wrote on his office’s Twitter account.

Giffords’ jump will be broadcast Thursday on NBC’s “Today” show.

In Tucson, about 100 residents attended a ceremony Wednesday morning outside the University of Arizona Medical Center, where the injured were treated. A bell was rung once for each victim as the Rev. Joe Fitzgerald spoke to the crowd.

“Today, we gather to remember the tragic day three years ago when our community was deeply wounded,” he said.

Other ceremonies and moments of silence took place across the city.

“I think the commemorations are, in large part, recognition of our community’s collective care and compassion and grit to go on,” Tucson Mayor Jonathan Rothschild said.

Pam Simon, 66, who was a Giffords aide at the time of the attack and suffered a gunshot wound to the chest, reflected on the shooting with crisp memories, but also a positive outlook.

“When we stop on an anniversary to really reflect, sometimes it opens the wounds a little bit,” she said. “But it’s also gratifying in a way to see the community come out again and remember.”

Giffords, meanwhile, has become a leader of Americans for Responsible Solutions, a national organization she founded with her husband to rival the powerful pro-gun lobby.

The group has struggled to bring about major change in its first year of existence, but the couple is confident they’ve laid the groundwork for success in future election cycles.

Giffords and Kelly formed their organization just weeks after the massacre in Newtown, Conn.

Since then, Congress has done nothing to tighten the nation’s gun laws. Some states, including Colorado and Delaware, pushed ahead with their own gun-control measures, while others like Arizona, Giffords’ home state, moved in the opposite direction, passing a law that requires municipalities to sell weapons surrendered at buyback programs instead of destroying them.