Each attendant parking facility shall comply with the following:
A. At each closing time of such facility, each unlocked vehicle remaining in or upon such facility shall be securely locked if a key therefor is available, and such key shall be deposited with a responsible person at a safe and convenient place approved in advance by the transportation official, to be delivered to the person who parked the vehicle upon the surrender of the parking receipt or ticket therefor.
B. Whenever a vehicle is found in or upon any such facility unlocked and with its key available in or about the vehicle and there is no attendant in or upon such facility, it shall be presumed that the facility is closed and that the vehicle was unlocked and remaining in or upon the facility with its key available at closing time. (1962 Code § 6-16.01 et seq.)