HONG KONG (CBS) – An engineering vessel caught in a tropical storm off Hong Kong snapped in two on Saturday and rescuers were trying to help crew members to safety before it sank into the choppy waters.

The Hong Kong Government Flying Service released dramatic video of heir staff wynching crew members from the stricken ship and into a helicopter. Authorities said 30 people were on board and three had been rescued so far.

Search operations were underway for the other crew members as tropical storm Chaba passes through the area some 300km (200 mioles) southwest of the city.

Chaba skirted the global financial hub, bringing heavy rain and wind, restricting public transport and forcing many businesses to close. The city’s weather forecaster lowered the storm warning to signal No 3 on Saturday afternoon as Chaba was set to make landfall near Zhanjiang in China’s Guangdong province.