When George Sodini burst into Heather Sherba's aerobics class and started shooting at a mirrored wall, her first instinct was to hit the floor.

But she knew that if she stayed there she might die.

"I was like, oh my God, he's going to try to kill all of us," she said. "I knew if I pretended to lay there and be dead, he could just keep shooting bullets no matter what. I had to get up and run for it."

As she got to her feet, Ms. Sherba caught the gunman's eye. He pointed his 9 mm handgun at her.

"That's when he shot me."

A shard of shrapnel hit her front tooth, chipping it in half. A bullet tore through her right thigh, grazing the inside of her left leg.

Ms. Sherba dropped again, and crawled three feet through the classroom's glass doors. She could feel the blood rushing out of her and saw it pooling on the shiny wooden floor.

"The only thing that went through my head was, I'm 22 years old and I'm about to get shot and killed by somebody I don't even know," Ms. Sherba said yesterday from a hospital bed at Allegheny General Hospital.

With her mother and younger sister in plastic chairs nearby, the striking redhead was in good spirits, hopeful she would soon return to her home in Collier.

But white bandages taped to her right thigh and a brown burn mark on her left were reminders of the chaotic minutes at LA Fitness Tuesday night when she did not know if she would live or die.

The night started out like many of Ms. Sherba's, at home, until she got an invitation from a friend to come work out at the sprawling fitness center on Washington Pike. There was a Latin hip-hop dance class, the friend said, and did she want to join?

Ms. Sherba said yes and showed up about 7:30 p.m., to beat the crowd to the popular class. It started promptly at 8 p.m., with about 30 women dancing to a salsa number. Ten minutes into the class a white man in black clothing walked into the back of the room, toward the left.

"I just thought it was someone who worked at LA Fitness or a maintenance person," Ms. Sherba said. "The next thing I knew all the lights went out."

She wasn't concerned; instructors sometimes turn the lights out in hot fitness rooms, or maybe there was a problem with the electricity. The class instructor, Mary Primis, headed toward the switch to see what was wrong.

"I heard a big crash that sounded like a light bulb exploding," Ms. Sherba said. "A bunch of shots were being fired at the mirrors in front of us. I saw bullet holes in the mirrors. I just hit the floor to take cover."

Pressed against the wood, she saw Mr. Sodini to her right a few feet away. She started to run.

"I had seen him shooting at the woman in front of me toward the door, so I was like, I'm going to have to be dodging bullets."

Suddenly, she was struck, crawling out the door and around the corner where she crouched behind a weight-lifting machine. But she was wearing black capri sweatpants and a hot pink T-shirt, and she feared the gunman might emerge from the workout room, find her and shoot her again.

"I thought for sure I was dead," she said. "When I was hit I thought he was going to shoot me again."

Mr. Sodini had likely already shot himself in the head. But Ms. Sherba didn't know that.

The pain from the wounds began to throb. She muttered softly, "What do I do? What do I do?"

A recent Robert Morris University nursing school graduate, Ms. Sherba knew what was happening. She knew she was losing blood. And she knew her adrenaline would help propel her.

With blood still gushing from her leg, Ms. Sherba hobbled to the doors of the locker rooms, where she collapsed. Dozens of people, some screaming, had already fled the building.

She called out for help to a man who ran past, but he just stood there, looking at her.

"He was in just as much shock as I was."

From the ground, she spotted her boyfriend's green shorts. Brian Bogats, who had been lifting weights in another part of the gym, had returned to the aerobics room, searching for her.

"I screamed, Brian, I've been shot, help me," she said.

He took off his T-shirt and tied it into a tourniquet, as Ms. Sherba instructed. He and another man carried her outside, as she screamed "Oh my God, I am going to die. I am going to die."

In what seemed like an endless ambulance trip to Allegheny General, the nurse in Ms. Sherba started asking questions.

What pain medications could she take?

What was her blood pressure and pulse?

"Once he told me, I knew I was going into shock," she said. During the fracas, Ms. Sherba didn't cry. In nursing school, she'd dealt with her share of wounded people, including gunshot patients.

But as paramedics wheeled her past the hospital doors, the night's horror began to sink in.

She broke into tears.