Timothy Caldwell told ABC11 Ellis' professional wisdom and expertise commanded attention.
"The knowledge that he had was unprecedented," said Caldwell, who is a senior firefighter for Raleigh Fire.
"I attribute just about everything I know as far as the fire department from him," said Caldwell. "He made you think about not only how to do it and how to do it correctly. But why are you doing it that way."
On Monday, the casket carrying Lt. Greg Ellis arrived to Lea's Funeral Home in Raleigh.
Around noon, the veteran firefighter's body led a 20 minute processional of first responders down I-440 East from the medical examiner's office.
Off-duty Raleigh firefighter killed in multi-vehicle crash along I-540
It's where doctors are trying to determine if a medical issue caused him to crash Sunday.
The wreck happened in the middle of the day on Six Forks Road near Interstate 540.
Highway patrol said the off-duty Raleigh firefighter veered out of his lane, and into two vehicles before becoming airborne, slamming into a third vehicle stopped in traffic.
Colleagues are stunned by how this could have happened.
Ellis had been a Raleigh firefighter since 2008. He was assigned to the Ladder 8 station in Southeast Raleigh, also serving as Fire Academy instructor.
Ellis was 49 years old.
Funeral arrangements will be updated at this link.