The victims were on their way to sell their produce in the town proper of La Libertad, 104.6 kilometers from the capital city of Dumaguete, when they met the tragedy.
PO2 Allan Ray Bulandres said only 12 of the 15 fatalities were identified as of press time.
Bulandres said the six-by-six truck, which had picked up the victims from various villages, lost its brakes, sending it plunging into the ravine in Sitio Maiti, Barangay Guisob.
The truck driver, identified as Burdik Nenoy, was unharmed and was detained at the La Libertad police station.
Bulandres said Thursday is market day in La Libertad and its mayor, Jocelyn Lim-Kaichong, as part of her Project Tabu, provides farmers with transportation to bring their produce to the town proper. Antonieta Lopez, AP