SANTA ANA – At first, Lyn Hiner thought it was a bug bite when she felt a sudden sting on her right thigh.

She gave her thigh a swat and the next thing she knew flames shot from her shorts where she stood in her San Clemente kitchen, eating an orange and attempting to plan the evening birthday date with her husband, Rob.

“Lyn sounded panicked,” Rob Hiner said, sitting next to her on her hospital bed at the Grossman Burn Center at Western Medical Center Santa Ana. “She turned around and I saw flames coming from her pocket. I went to smack it and at the same time the house filled with smoke. Lyn screamed, ‘get it out,’ it was terrifying and confusing all at once.”

In seconds Lyn Hiner dropped to the ground and rolled but the flames would not extinguish. An acrid smell, like firecrackers, filled the home and breathing was difficult.

Frantically the couple tried to bat the flames out. Then Rob yelled for Lyn to open her pants and he pulled as hard as he could to get them off.

Rocks fell from her pockets — the ones Lyn and her two daughters, who are nine and 11, collected at Trestles at San Onofre State Beach several hours earlier.

An oily-like residue dripped to the hardwood floor as well, starting fires in the kitchen. Lyn ran to the sink, her right hand scorched, searing with pain.

As smoke filled the home, the Hiner’s youngest daughter, who had been reading in the front room, ran out the front door. The family’s border collie-mix bolted from the front door and across the street to Bonita Canyon Park. Their older daughter chased after the dog.

With screams coming from the home, next-door neighbor, Jason Young, Chief of OC Lifeguards, jumped the railing between their homes and rushed in to help.

Rob called 911 and Orange County Sheriff’s Deputy Jeremiah Prescott was at the home on Avenida Estrella within minutes. Orange County Fire Authority firefighters and paramedics rushed to the scene. Within minutes, Lyn and Rob were in the ambulance and the still sparking rocks were in a coffee cup in a corner of the ambulance as they rushed to Western Medical Center in Santa Ana. The couple prayed together asking God for guidance.

Since the incident — which occurred Saturday — Lyn has been treated for second and third degree burns. She’s undergone two surgeries for skin grafts on her right leg, right hand and the inside of her left thigh. She’s endured pain and emotional trauma and will require weeks and months of physical therapy.

The couple’s home has been inspected by Hazmat teams from Orange County Public Health. The kitchen floor has been ripped out and the walls and nearby bathroom have been sanitized. The home is uninhabitable until construction can be done to restore the kitchen and all the appliances.

The rocks, described as a smooth orange colored one and a smaller green one, have been sent to a state lab for testing. Initial tests at the county health department revealed phosphate. Chemistry experts said the rocks may have been coated with phosphorous, a substance that can spontaneously ignite when exposed to oxygen.

Meanwhile officials from the U.S. Department of the Navy and from Camp Pendleton say they don’t believe the substance stems from any military training exercises. The San Onofre Nuclear Generating Station is believed to not play a role in the source of the burning rocks, experts said on Thursday.

Despite the freakish accident, The Hiner’s say their faith in God and the deeds of so many, including the first responders from the Orange County sheriff Department and the Orange County Fire Authority, have helped them through the ordeal.

“We know bad things happen to many people,” Lyn Hiner said. “I’m thankful God carried us through this. That Jason, the deputy, the firefighters and the doctors, the hospital staff, have all been with us. I know there are patients here that are going through a lot more than I am. I’m grateful it wasn’t the girls and that it didn’t happen on the freeway on our drive home.”

Lyn Hiner said the Saturday at the beach is something the family does often. They had gone to the tide pools to look for interesting rocks, shells and other beach artifacts. It’s an activity Lyn and her family has done for many years. As an artist, Lyn Hiner said she has always been drawn to unique-looking nature.

The rocks her daughters collected at the beach that day appeared smooth, slightly white and granite-like but nothing odd. She carried them for her daughters because they were in swimsuits. Then, for about three hours the family spent times with friends at a nearby house and their pool.

They drove home with plans to call the babysitter and go out for Rob’s birthday which had been the Monday before.

“That’s how quick it went from ‘let’s get a sitter, to me sitting on the front porch with my hand and leg torched,” Lyn Hiner said.

Contact the writer: 949-454-7307 or eritchie@ocregister.com or twitter.com/lagunaini