Jeffrey and Nancy Thomas can only imagine how their son, Clayton, would have planned the final two weeks of his life, but both believe that his script couldn’t have been much better.

Clayton David Thomas, 16, watched an older brother graduate from high school two weeks ago. He spent a few days in Fort Collins, Colo., where he grew up, meeting the family of his sister’s fiance, visiting amusement parks and hanging out with old friends. He attended his sister’s wedding Saturday at the Salt Lake Temple, sang a cappella at the wedding luncheon and visited the family cabin in Timber Lakes the next day with his brothers, mother and maternal grandparents.

Lastly, there was a whisper of “I love you, too” from a sleepy Clayton to his father just before the latter left for a business trip to Chicago on Sunday morning.

Jeffrey and Nancy Thomas were devastated by Clayton’s death Sunday evening from accidental exposure to carbon monoxide at the family cabin, but they took solace in knowing that his last few days were some of the best days of his life.

“When you just look at him, as hard as this is, you try to [think about] that last week in your life; what would you do? He did everything that I know he would have wanted to do,” Nancy Thomas said.

After walking through the woods with two of his brothers Sunday, Clayton went upstairs to take a shower. Nancy Thomas began to worry after Clayton hadn’t come downstairs after 30 minutes with the shower still running, and she knocked on the restroom door. She received no answer and opened the door, finding Clayton unresponsive in the tub.

Clayton’s older brother, Dallin, applied CPR. Paramedics were called and attended to Clayton, but their efforts to revive him were unsuccessful. He was rushed to Heber Valley Medical Center, where he was pronounced dead upon arrival.

The Thomases suspect that a gas hot water heater located in the upstairs restroom caused Clayton’s death, although they said that they had no problems with it during past visits to the cabin, which they’ve owned since the mid-1980s.

“It must have been running full steam and just put off enough fumes,” Jeffrey Thomas said.

Clayton, the fourth oldest of six siblings, was born July 15, 1992, in Murray, but moved to Fort Collins only three days later. Three years ago, the Thomases moved to Falmouth, Maine, and he attended Falmouth High School, where he remained active in an assortment of activities.

He performed in plays and musicals, played the piano and drums, sang and participated in several sports, including soccer, track, wake-boarding and snowboarding. He maintained good grades and was an Eagle Scout. He was active in the LDS Church and planned to attend Brigham Young University after graduation and embark on a two-year mission upon turning 19.

But aside from being a model student, Clayton was also known as being a peacekeeper.

“He was always happy,” Nancy Thomas said. “He made everyone around him feel good.”

In addition to his parents, Clayton is survived by brothers Tyler, Dallin, Tanner and Aaron, sister Whitney Lewis and her husband, Ryan, paternal grandparents D. Ray and Carol Thomas of Holladay and maternal grandparents Harold and Marie Hymas of Heber City. His funeral will be held at 11 a.m. Thursday at Holladay South Stake Center, with a viewing to be held one hour before services.

Clayton’s friends honored his memory by starting a group on Facebook entitled “In Loving Memory of Clayton Thomas.” Friends, teachers and teammates also held a memorial at Falmouth High School on Tuesday night.

Between the multitude of phone calls and e-mails expressing condolences and tributes, Jeffrey and Nancy Thomas are certain their son’s memory will live on through the lives he left a positive impact on.

“He always seemed to bring people up to a good level; he didn’t make people feel bad,” Jeffrey Thomas said. “He always had a standard in life that he followed, and he lived up to that.”