Boy, 4, Has Prosthetic Leg Stolen During His First Visit to the Beach

"I was very mad but I was mostly just worried about him. I didn't how how he was going to feel and how it was going to affect him," his mom said.

Life's a beach, but not for this California boy who had his prosthetic leg stolen during his first-ever trip to the shore.

Read: 7-Year-Old Boy With Two Prosthetic Legs Meets Dolphin With Prosthetic Tail

Liam Brenes, 4, had never been to the beach before when he visited Crystal Cove with his father and older brothers. Before taking a dip in the tide pool, the boy put on an old prosthetic leg, which he has outgrown, to keep the new one from getting wet or dirty.

Leaving the leg and other items such as a camera and Liam's glasses on top of their cooler in the sand, the family hit the water.

But when they returned, the personal items — including the leg — had been stolen.

"They just took my clothes, and my shoes, and my prosthetic leg," Liam said in an interview with KCBS.

His father, Frank Brenes, wrote on Facebook, "My four year old son is now without his leg because of these people... I am crushed."

Liam's mother Amanda McFarland told she felt angry and helpless when she heard what happened at the beach.

"I was very mad but I was mostly just worried about him," she said. "I didn't know how he was going to feel and how it was going to affect him."

According to Brenes, Liam was diagnosed with FATCO syndrome, a rare condition that caused him to be born with only two fingers on his left hand, and no right fibula bone.

At just 1 year old, the boy had his leg amputated above the ankle. To help him get around, he wears Star Wars- or pirate-themed prosthetics.

Read: Little Girl Cries With Joy as She Receives American Girl Doll With Prosthetic Leg, Just Like Her

But since his custom leg was stolen, his mom said they are still working out the logistics of replacing it.

McFarland explained the most basic functional prosthetic could cost upwards of $10,000, but they are lucky enough to have the help of Shriners Hospital for Children in Los Angeles, who conducted the original amputation and often help families fund prosthetics using donations.

"Little guy has such a better attitude about it than me," Brenes wrote. "He's just like, 'I'll ask Santa to put something important on my list.'"

Watch: College Students Create 'Frozen'-Themed 3D Printed Prosthetic for Girl Born Without Hand