HA LONG: At least 34 people have died and several remain missing after a tourist boat capsized in Vietnam’s Ha Long Bay during severe weather.

The vessel, Wonder Seas, was carrying 53 people—mostly Vietnamese families from Hanoi—when it was hit by a sudden storm on Saturday afternoon, according to the Vietnamese Border Guards and navy.

So far, 11 survivors have been rescued from the water. Heavy rain and rough conditions have hampered the ongoing search efforts.

An eyewitness described the storm as abrupt and violent, with hailstones “as big as toes,” accompanied by torrential rain, thunder, and lightning.