Police are searching for the drivers of three vehicles who may have witnessed a fatal crash last week that claimed the life of a Wellesley man out for a bicycle ride.

Alexander Motsenigos, 41, was riding his bike on Weston Road near the intersection of Linden Street on Friday at about 2 p.m. when he was allegedly struck and killed by an 18-wheel dump trailer, according to Wellesley police. The truck did not stop.