Jeff Ferguson misses his stepson most in the mornings.
That's when he would drive Derek Benjamin Greer to Coronado High School, where he was a freshman.
"He was actually my alarm clock, because he woke me up every morning at 6:30," Ferguson said.
Derek, 15, and Natalie Partida, 16, were found dead Sunday morning, their bodies left lying on the shoulder of Old Pueblo Road in rural El Paso County near the Pikes Peak International Raceway. Their deaths have been ruled homicides by the El Paso County Coroner, but no suspect information has been released. No arrests have been announced.
Derek's mom, Heather Ferguson, and his stepfather are struggling to understand how and why they were killed.
On Thursday, just days after his death, she said she often feels empty and numb. It's been a blur, but also, "living every second is near unbearable."
"A part of me is gone - part of my heart, part of my soul," she said. "Every morning, it's just a new wave of, 'This is reality.' My life is without him, and I don't know how to live that life."
Natalie was a sophomore at Coronado High School, a grade above Derek.
They were best friends, Heather Ferguson said.
"They were inseparable. They were always together. They loved each other," she said. "They were their own little team, you know?"
"I don't understand how somebody could do something like this to two innocent children at all, what anyone could do, period - young, old - to deserve to have their life taken."
The house where Derek lived with his four younger siblings is littered with memories of him. At 13, the second-oldest child understands what's happening, his parents said. For the most part, the others don't.
"Just love your kids. Know what they're doing - stay involved," said his mother. "Just enjoy every second, because you never think it's going to be the last one. You could never possibly imagine."
Jeff Ferguson said he hopes for some amount of closure as the investigation progresses.
"I just hope one day, the person or persons involved, who committed this crime, they realize how many lives they've destroyed and they have remorse for that," he said. "They didn't just take two people's lives - they literally destroyed hundreds of lives."
Their memories of happy times spent with Derek help to sustain them, they said. Dozens of photos of Derek covered tables in their home on Thursday.
Derek was always talking and was often the center of attention, his stepfather said.
"If you were in a room with him, you would know he was there," he said. "He would make an impression on you. You would remember him."
The outpouring of support has made them realize how many people Derek impacted throughout his life.
"I hope it can be an eye-opener for kids that there are real dangers out there," Heather Ferguson said of his death. "At that age you think you're invincible, you know what I mean? That you have your whole life ahead of you. It's horrible - he was robbed of that."
Visitation for Natalie, who had five siblings, is scheduled from 4 to 5 p.m. Sunday, with a Rosary to follow, at The Springs Funeral Services, 3115 E. Platte Ave. Her Mass of Christian Burial will be at 10 a.m. Monday at St. Mary's Cathedral, 22 W. Kiowa St.
Derek's viewing will be from 4-7 p.m. on March 24, at Angelus Chapel Funeral Directors, 1104 S. Circle Drive, with a service to follow on Saturday at 2 p.m.
GoFundMe accounts have been set up for the teens.
Contact Ellie Mulder: 636-0198