On Sunday 4 April 2021, 46 year old monk Phra Ajarn Manas, on his annual pilgrimage from Nakhon Sawan province, entered Tham Phra Sai Ngam to meditate. This 3 km long cave is on the western edge of the Thung Salaeng Luang National Park, 6 km north of Noen Maprang in Phitsanulok province. While he was in the cave a heavy thunderstorm caused a seasonal sump, 400 m from the entrance, to close trapping him in the cave. As the monk was planning to spend a long time in the cave (he reportedly had some food with him) the alarm wasn’t raised until noon on Tuesday 6 April.
The first responders were the local Prasat Boon Sathan rescue foundation and rangers from the National Park. They entered the cave around 17:00, but were stopped by the sump and were out of the cave by 18:00. Rescue operations were then suspended overnight while a full scale rescue operation was initiated, headed by the Governor of Phitsanulok.
At 07:00 on Wednesday 7 April there was a planning meeting and by 08:30 a team of 17 local rescuers, including several divers, were on their way into the cave. Meanwhile outside the cave many organisations and volunteers had been mobilized including, but not limited to, Provincial, District and local administrations, the Department of Disaster Prevention and Mitigation, the Thai Army, local rescue foundations, medical teams, the Royal Forest Department, the National Parks Department, a national rescue team from Bangkok, provincial and tourist police. A check-in station in the nearest village had been set up where volunteers and rescuers had to have their temperature taken, register, have their bona fides checked and be issued a pass. Access to the cave was controlled with only one route in and two checkpoints between the road and the cave. At the cave there were ambulances, a generator truck, Army Humvees and most Thai TV stations had a crew there. An estimated 300 people were involved.
In the cave four divers from the local rescue team managed to pass the 20 m long and 4 m deep sump and found the monk. Phra Ajarn Manat was given an impromptu diving lesson and was then dived back through the sump. After a short rest, an energy bar and a medical check-up the monk then walked out of the cave, leaving the site in an ambulance at 11:30. Amongst the rescuers three of them sprained their ankles in the streamway, one of them seriously enough to require stretchering out of the cave.
With the monk successfully extracted the Governor and rescuers gave press interviews and by noon the whole operation was being rapidly disbanded.