Lauda Air Flight 004 breaks apart in mid-air and crashes in the Phu Toei National Park in the Suphan Buri province of Thailand, killing all 223 people on board.

Lauda Air Flight 004 (NG004/LDA004) was a regularly scheduled international passenger flight from Hong Kong, via Bangkok, Thailand, to Vienna, Austria. On 26 May 1991, the Boeing 767-300ER operating the route crashed following an uncommanded deployment of the thrust reverser on the No. 1 engine during the climb phase, causing the aircraft to enter an aerodynamic stall, uncontrolled dive, and in-flight breakup, killing all 213 passengers and ten crew members on board. It is the deadliest aviation accident involving the Boeing 767, and the deadliest aviation accident in Thailand's history as of 2025. The accident marked the 767's first fatal incident and third hull loss. Formula One world motor racing champion Niki Lauda, who founded and ran Lauda Air, was personally involved in the accident investigation.

Phu Toei National Park (อุทยานแห่งชาติพุเตย) is a national park, with an area of 198,422 rai ~ 317 square kilometres (122 sq mi) in Dan Chang District of Suphan Buri Province, Thailand. It has been the 86th national park since 30 September 1998.

Suphan Buri located in the central region of Thailand, is one of the country's 76 provinces, the first-level administrative divisions. Neighbouring provinces are Uthai Thani, Chai Nat, Sing Buri, Ang Thong, Phra Nakhon Si Ayutthaya, Nakhon Pathom and Kanchanaburi. As of 2018 the province counted a population of around 848,700, representing about 1.28% of the country's population.

Thailand, is a country in Southeast Asia on the Indochinese Peninsula. It is officially the Kingdom of Thailand and historically known as Siam, the official name until 1939. With a population of almost 66 million, it spans 513,115 square kilometres (198,115 sq mi). Thailand is bordered to the northwest by Myanmar, to the northeast and east by Laos, to the southeast by Cambodia, to the south by the Gulf of Thailand and Malaysia, and to the southwest by the Andaman Sea; it also shares maritime borders with Vietnam to the southeast and Indonesia and India to the southwest. Bangkok is the state capital and largest city.