The incident occurred at 11:28 a.m. on Sunday when the boat, carrying 18 people—16 foreign tourists, a tour guide, and the boat captain—overturned, according to Nation Thailand.

All passengers, including the captain, were rescued without injury.

However, the tour guide was found unconscious from water inhalation and was rushed to a local hospital where she was pronounced dead at 12:30 p.m., Khaosod English reported.

The victim was identified as Thassawan, 44, a licensed tour guide.

Local police have launched an investigation into the cause of the accident.

The tragedy occurred just a day after a separate boating incident in Vietnam’s Ha Long Bay, which left 36 tourists dead and three missing.