Police Col. Jitkasem Sonkham says several motorcycle drivers and their vehicles fell into the Pasak river Sunday while they were crossing the suspension bridge in Ayutthaya province's Tha Ruea district.
Authorities found four bodies under the rubble. Twelve people were injured.
Jitkasem says the cement bridge was built a few years ago for pedestrians and small vehicles to cross but has not been well maintained. He says investigators believe that the bridge was not over capacity at the time the accident happened but that it was in poor condition.
Tha Ruea is 109 kilometers (68 miles) north of Bangkok.
Take ABC13 with you!
Download our free apps for iPhone, iPad, Android and Blackberry devices