More than 100 Red Cross facilities, including this one on the West Side, offered free hands-only CPR and first aid training.
Organizers say several bystanders knew life saving skills, helping Giffords and others wounded in the Tucson shooting.
A Red Cross survey found that one in four people have found themselves in a situation where someone needed CPR.
That's where classes like this can help.
"It gives people basic, fundamental lifesaving skills so that in the event of an emergency they'll be confident enough to take the action necessary to save someone's life," a Red Cross spokesman said.
One woman who took the class said she didn't want to just stand by and watch in the event of an emergency.
She says Saturday's class has inspired her to take more.