Tuk tuk driver Somkiert Thepabut, 47, was taken to Ramathibodhi Hospital to be treated for head injuries sustained from one of the falling poles.
Another pole toppled in the direction of a house belonging to Ritdamrong Disakul na Ayutthaya, a grandson of Prince Damrong Rajanubhab.
Preliminary investigation suggested that the wall collapsed due to the vibration caused by the demolition.
Boy Ocean Star Co Ltd, which is overseeing the demolition, has said it will pay for the damage.