Police and rescue workers were called to an accident about 10 am in Phetchabun, Province after a tour bus taking a group of elderly on a tour of Khao Kho overturned on Sunday morning, killing one of the tourists and injuring about 20 others. The passengers told police investigators that the double-decker tour bus was taking 43 elderly tourists from Bangkok to visit several temples and attractions around Phetchabun. On their return from Khao Kho on Sunday, the bus suffered a brake failure while climbing uphill, causing it to roll backward, crashing into a roadside barrier before overturning. The vehicle came to rest on its side, blocking three of the four traffic lanes. One female tourist, Ms. Bussakorn Thongsri, 64, of Bangkok's Nong Khaem district, was killed, while 20 other senior passengers were injured, they were admitted to Lam Sak Hospital. Shortly after the accident occurred about 20 soldiers from the 28th Cavalry Battalion arrived to help move the bus to the side of the highway. The organizer of the group tour later sent a bus from Lom Sak district to take the remaining uninjured passengers back to Bangkok. Police and Transport officials are investigating the Buses braking system and said charges and fines could be levied against the Tour Bus operator if they fine any negligence of maintenance. Thailand's roads are among the world's deadliest and accidents are common, especially on buses traveling late at night.