The Marysville community is mourning the loss of a 6-year-old boy and his parents after their family vacation ended in tragedy.

The Marysville community is mourning the loss of a 6-year-old boy and his parents after their family vacation ended in tragedy.

James and Amy Kerker knew their son, Lucas, might not live a long life. But they were determined to make it a full one.

Having an airplane was one way the Union County couple made vacations easier for their only child, who was born with ataxia-telangiectasia, a rare genetic disease that causes progressive loss of muscle control, immune-system problems and a high rate of cancer.

On the morning of Monday, June 30, after taking off from Rocky Mountain Metropolitan Airport in Broomfield, Colo., something went tragically wrong.

James Kerker, 41, a former U.S. Air Force pilot, was following Interstate 70 west toward the mountains when witnesses reported seeing the family's single-engine Piper Cherokee turn quickly to avoid a ridge around 8:45 a.m. The plane crashed and caught fire at Loveland Valley Ski Area, killing everyone on board.

The problem is all too familiar to Colorado authorities. Several planes, including one carrying the 1970 Wichita State football team, have gone down in similar crashes, said Capt. Randy Long, of the Clear Creek County sheriff's office.

"As they're following I-70, the Continental Divide is not readily apparent until you round the corner," Long said. "If you don't have the altitude at that point, there's no way a single-engine aircraft will have enough altitude to fly over the ridge line."

Amy Kerker's sister, Leslie Lefeld, of New Bremen in Auglaize County, said the family took frequent trips. Kerker, 38, devoted everything to her son, who was expected to require a wheelchair by age 10 and not to live past 18, Lefeld said.

The Kerkers made a video when Lucas was first diagnosed and posted it online (watch video below). The quiet family wanted to bring awareness to A-T, a so-called "orphan disease" -- one so rare that drug companies don't bother to research medications. Lucas was one of 500 children in the United States with the disease, they said.

At the end of May, his family held "Lucas's Third Annual Hope With Every Step" 5K race, raising more than $25,000 for A-T research.

Just two days before the accident, Amy Kerker wrote on Facebook they were listening to Conway Twitty while driving through the Rocky Mountains. A friend commented, "Be safe."

Kerker, a pediatric surgery nurse at Nationwide Children's Hospital in Columbus, had just watched a young man succumb to A-T, writing June 15 that his bravery and sense of humor had touched her and would stay with her the rest of her life.

Lucas had just finished kindergarten at Mill Valley Elementary School. In January, he was designated a junior state trooper by the Ohio State Highway Patrol.

His aunt said he was looking forward to the monthlong trip out West, even as his illness was taking its toll.

"They wanted to make sure he got his life experiences in," Lefeld said.

"He was too young to understand, and didn't let it stop him," she added. "He would try anything. He was just full of life, just a happy kid."

The day of the accident, Marysville Superintendent Diane Mankins sent out a letter saying those in the district are heartbroken and have the family in their thoughts.

"Marysville is a close-knit community, and this impacts us all," she wrote. "Lucas was a kindergarten student at Mill Valley last school year and had a smile that would light up a room."

Underwood Funeral Home, 703 E. Fifth St., is handling the arrangements, which had not been finalized as of ThisWeek's press time July 3.

Amy Rogan contributed to this report.