Ha Long Bay, Vietnam. 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.

A survivor named Dang Anh Tuan said a storm quickly covered the sky, bringing high winds and pouring rain.

Tuan said the passengers asked for the boat to turn back to shore, but the crew reassured them they were almost at their destination and kept the boat moving forward.

“It rained for about 15 minutes, and then the boat started to shake vigorously, tables and chairs were jostled around, and seconds later the boat overturned,” the 36-year-old fire extinguisher salesman said. “Water gushed in and I lost all orientation.”

“I tried to breathe. But more water came in. I took a deep breath, got rid of my life vest and dove down. I saw a streak of light and followed it to swim out, escaping the boat, and then I climbed on the overturned boat to look for help,” he said.

Tuan and several other people survived by clinging to the capsized boat and its propellers, waiting another two hours before the rain stopped and rescuers arrived.

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.