HA LONG BAY, Vietnam (AP) — A boat carrying tourists capsized during a sudden thunderstorm in Vietnam on Saturday afternoon during a sightseeing excursion, killing 37 people, state media reported. Five others remain missing.

The Wonder Sea boat was carrying 48 passengers and five crew members — all of them Vietnamese — on a tour of Ha Long Bay, a popular destination, according to the reports.

Rescue workers saved 11 people, and recovered the dead near the site of the capsizing, VNExpress newspaper said. Authorities revised the figure after earlier reporting that 12 people had been rescued.

The boat turned upside down because of strong winds, the newspaper said. A 14-year-old boy was rescued after four hours trapped in the overturned hull.

The newspaper said that most of the passengers were tourists, from Hanoi, including about 20 children.

A tropical storm is also moving toward the area. A national weather forecast said that Storm Wipha is expected to hit Vietnam’s northern region next week, including Ha Long Bay’s coast.