The driver, Chris Hulett, 27, of Newport Beach struck the two, police said. The investigation is still open and no charges have been filed, police said.
Koontz survived with multiple injuries, including a broken pelvis, arm and two sprained ankles. Unable to walk to the podium, Nathan made a statement from his wheelchair at the back of the auditorium.
"I'd rather be doing nothing with you than something with anyone else," Koontz said in a letter to Heather.
He was determined to get released before Saturday, father Jerry Koontz said.
Heather's death was one of several along the stretch of coastal highway.
On Aug. 24, Candace Tift was struck by a car and killed while riding her bike along West Coast Highway in Newport Beach.
Tift, a teacher at Eastbluff Elementary school, was riding on the sidewalk when Irvine resident Janene Johns, 52, veered off the road.
Police say Johns was under the influence of prescription drugs at the time, but no charges have been filed.
The accident, although unusual, reinforces the need for increased caution on the road, Newport Beach Police Sgt. Bill Hartford said.
Don't speed, obey the traffic laws, don't drink and drive, and stay aware of how prescription medicine can impair driving, Hartford said.
Huntington Beach City Council Member Gil Coerper said he considers the highway safe to walk along.
"Being a police officer, I have investigated many problems on PCH, many people make mistakes making turns," Coerper said. "They get impatient."
"I feel sorry for the parents, and the family," Coerper said. "Even one loss on the highway is too much."
"My heart has been ripped from my chest," Chris Stamm said.
"Maybe something good will come of this. Hopefully they make the road safer for people."
Does Pacific Coast Highway need more pedestrian safeguards? Call our Reader's Hotline at (714) 966-4691 or send e-mail to hbindependent@ latimes.com. Please spell your name and include your hometown and phone number for verification purposes.