In a matter of minutes, a quiet Saturday morning in Tucson turned into a tragedy.

Six people died and 13 were injured, including U.S. Rep. Gabrielle Giffords, when a gunman opened fire on Jan. 8 at a "Congress on Your Corner" event in front of a northwest-side Safeway.

Jared Lee Loughner, 22, has been charged with two federal counts of first-degree murder in the deaths of U.S. District Judge John M. Roll and an aide to Giffords, and three counts of attempted murder, of Giffords and two other aides who were injured.

Giffords remains hospitalized after a bullet entered and exited the left side of her brain. She is still on a breathing tube, but she has opened her eyes and moved her arms and legs, encouraging her doctors.

This timeline shows how the shooting unfolded, how local citizens helped subdue the shooter, and how quickly Giffords was treated and underwent surgery at University Medical Center.

Timeline of events

9:58 a.m. Giffords tweets from her iPad: "My 1st Congress on Your Corner starts now. Please stop by to let me know what is on your mind or tweet me later."

9:59 a.m. A taxi drops off suspected shooter Loughner at the Safeway.

10 a.m. Giffords' "Congress on Your Corner" begins in front of Safeway. About 20 people wait in line.

10:10 a.m. The shooting begins. The gunman fires at Giffords point-blank, hitting her in the forehead above her left eye, while she talks to constituents.

10:10 a.m. The gunman continues firing at those waiting in line to talk to Giffords.

10:11 a.m. The first 911 call of the shooting comes in.

10:12-10:13 a.m. An individual hits the shooter with a folding chair. The gunman reaches for another magazine to reload his Glock 9 mm pistol. But 61-year-old Patricia Maisch grabs the magazine first. The shooter tries to load another magazine in the gun, but the spring fails. Two men who were waiting in line, Roger Salzgeber and Bill Badger, tackle the shooter, subduing him. Badger grabs the shooter's left arm and twists it behind his back. Badger places his right hand between the shooter's shoulder blades and pushes him down. Maisch kneels on the shooter's ankles. Joseph Zamudio, 24, helps restrain the shooter's legs. They hold down the shooter for five or 10 minutes until a deputy arrives and places him in handcuffs. Six people are dying or dead. Badger, 74, is bleeding from a bullet graze to the back of his head.

10:12 a.m. Giffords intern Daniel Hernandez Jr. rushes toward Giffords and props her up to keep her from choking on her own blood. He applies pressure to the gunshot wound. He asks her a question and she squeezes his hand.

10:14 a.m. Northwest Fire Department dispatched to the shooting. Southwest Ambulance is dispatched.

10:15 a.m. The first sheriff's deputy arrives on the scene and detains suspect.

10:16 a.m. Paramedics arrive.

10:16 a.m. The suspect is taken into custody.

10:19 a.m. Northwest Fire arrives at scene.

10:21 a.m. A victim arrives at Northwest Medical Center.

10:41 a.m. Ambulance takes Giffords to UMC.

10:45 a.m. A second victim arrives at Northwest Medical Center.

10:48 a.m. - 11:10 a.m. Eight patients arrive at UMC, three by air, five by ground, including Giffords and 9-year-old Christina-Taylor Green. One patient arrives at Carondelet St. Joseph's Hospital and four arrive at Carondelet St. Mary's.

11:32 a.m. Giffords enters surgery for a gunshot wound to the head.

12:04 p.m. A Northwest Medical Center patient is transferred to UMC.

12:40 p.m. Second Northwest Medical Center patient is transferred to UMC.

1:40 - 2 p.m. Giffords comes out of surgery. She was shot through the head one time. About half of her skull was removed to relieve pressure from swelling of the brain.

2 p.m. At a UMC news conference, Giffords is described as being in critical condition. Trauma surgeon Dr. Peter Rhee says he is optimistic about Giffords' condition because she has been able to follow commands. UMC received 10 patients, including 9-year-old Christina, who is pronounced dead at the hospital.

3 p.m. Four of the five patients who were taken to Carondelet hospitals have been discharged. A St. Mary's Hospital patient has been transferred to UMC.

Sources: Pima County Sheriff's Department, witness accounts, University Medical Center, Arizona Daily Star archives