Scottsdale police identified those killed in the accident Saturday as 52-year-old Al Barela and 37-year-old Samantha Barela.
They were part of roughly 1000 bikers riding from Mesa to Scottsdale, all in the name of charity. But after this tragedy, many bikers say they'll never participate again.
Scottsdale police also say event organizers were advised to tell participants to stop at red lights if an officer wasn't present.
The Associated Press contributed to this story.