Riley had two daughters and four grandchildren.
He was exiting the train Wednesday, but his dog, Daisy, remained inside the train car as the door closed.
"It’s a little bit frightening that that could happen, and that there aren’t some sort of safeguards in place to prevent that from happening to anybody else," Jack Schulte told Fox 5.
DC METRO EMPLOYEE KILLED TRYING TO STOP SHOOTER 'HEROIC,' SUSPECT IDENTIFIED
Harold Riley was killed after his dog leash became caught in a closing Metro door. (Courtesy, Olivia Stark)
Harold Riley was killed in an accident at a DC-area Metro system station. (Reuters/Jonathan Ernst)
Harold Riley is survived by two daughters and four grandchildren. (Courtesy, Olivia Stark)
Police took the dog into custody soon after the accident, but Riley's daughter soon retrieved her. She told Fox 5 that she found a family to adopt the dog, as she had other animals to care for.
Pets are not allowed on Metro transit lines unless they are service animals. While Transit Police initially stated that Daisy did not appear to be a service dog, Riley's daughter said the dog was wearing its service vest at the time of the accident.