CHANDLER, Ariz. - The family of the Chandler mother hit and killed by a car as she was crossing the street with her kids Saturday is grieving her loss and crediting a helmet with saving her son's life.

Pamela Hesselbacher was walking home from the park with her son Ryan, 3, and daughter Audrey, 1, when they were hit by a driver on the crosswalk.

All three were taken to hospitals.

Pamela later died, while Ryan and Audrey remain in critical condition at Maricopa Integrated Health Systems.

Baby Audrey is suffering from head injuries and is in a coma, while Ryan has a broken arm and hips and has lacerations.

"This is the helmet he was wearing when they were hit by the car," said Tommy Kieran, Pamela's brother.

The family credits the helmet for saving young Ryan's life. Pamela put it on, even though the park was just around the block.

"I work with city of Seattle as a firefighter, and far too often we go to tragic events," Tommy said. "I have no doubt in my mind that this helmet saved his life and I know Pam did everything she could to make sure kids were safe and protected."

Pamela's mom, Jody Kieran, said nothing was more important to her daughter than her family.

"My nickname for Pamela was Pretty Pam, because my daughter was beautiful on the inside and outside," said Jody.

Pamela spent much of her time volunteering. The charity Hope Kids Corner was particularly close to her heart.

"In terms of selflessness, she was one of our leads in terms of community engagement," said Shea Allred, who worked with Pamela at General Mills.

The family is now rallying around Pamela's kids, for whom they have set up a GoFundMe, which they hope will not only help cover the costs of the hospitalization, but their future as well.

"These kids have a long road ahead of them, Ryan and Audrey. They deserve the best they can have. The GoFundMe page will help make sure they have anything they need," said Shannon Kieran, Pamela's cousin.