A memorial to Dave Tremaine at a candlelight vigil on June 16, 2014, at the school in Alexandria, Va. Tremaine, the principal of the school, died of cancer that day. (Thomas Kinder /PixJrPics.com)

On Tuesday afternoon, Hayfield Secondary senior Derek Kominars received his diploma, a feat that almost never happened.

At a candlelight vigil the night before, Kominars credited his success to former principal David Tremaine, who died Monday after a three-year struggle with colon cancer. Tremaine, 49, joined Hayfield in 2010, and Tuesday’s graduating class was made up of the freshmen from his first year as principal. One of them was Kominars.

“He believed in me even when other faculty thought otherwise, especially when I might not graduate,” Kominars, 17, said at the vigil in front of the school.

Stress, poor grades and discipline issues had stalled Kominars’s early career at Hayfield. By his sophomore year, he had a meeting with Tremaine in the principal's office.

“He said, ‘All right, I believe in you,’ ” said Kominars, who will attend Northern Virginia Community College next fall.

When Kominars walked up to the stage Tuesday to receive his diploma, he stopped, took off his mortar board, spun around and performed a back flip.

It was the kind of spontaneous act of joy that Tremaine was known to celebrate as principal, when he would greet students in the halls with high-fives and smiles. Tremaine’s absence was palpable in the Hayfield gym during the graduation ceremony. Interim principal Tracey Phillips led the crowd in Tremaine’s favorite display of Hayfield Hawks pride: flapping their extended arms like wings.

Tremaine’s wife, Robyn, wrote frequently about her husband’s Hayfield pride in an online diary documenting his struggle with cancer. His clothes were sorted into those that were orange, the school color, and those that were not. Tremaine was even known to wear orange sneakers to work.

Robyn Tremaine’s almost daily posts portrayed her family’s life after her husband’s cancer diagnosis. She called the blog Embracing the Roller Coaster.

“Someone told me that cancer is like a roller coaster,” she wrote. “We unwillingly boarded the roller coaster on August 3, 2011 – the day Dave was diagnosed with stage 4 metastatic colon cancer. There are lots of stories since that day. Some of which I hope to tell here.”

Some days she wrote about the times when she and Tremaine used to make pancakes together on weekend mornings. On other posts, she wrote about staring at CT scan images of possible tumors in her husband’s liver.

By early June, it became clear to Robyn Tremaine that her husband’s condition had worsened.

A June 11 post begins: “His skin now has a yellowish hue as do the whites of his lovely blue eyes. The skin on his legs and feet is pulled so tight that it’s starting to crack.”

The descent was swift, she wrote. A month earlier, Tremaine had accompanied her on long walks with the dogs through the woods. “This lifetime athlete now has to stop to catch his breath after walking from one room to the next,” Robyn Tremaine wrote. “I have this overwhelming feeling that we haven’t done all the things that we were supposed to do.”

She wrote about Tremaine’s last Father’s Day on Sunday in a hospital room, on pain medications and hooked to an oxygen mask.

She ended the blog with a final dispatch on June 16: “Today I completed the hardest and yet most important job I’ve ever had. I watched over Dave until after he took his last breath.”