Two passengers boats collided in the dark in the waters off Hong Kong last night, sinking one of the vessels and killing at least 36 people. Rescue workers say more than 100 people were pulled from the water and taken to the hospital, but they have not ruled out the possibility of finding more bodies, possibly even some who were trapped inside the ship.

The boat that sank was carrying around 120 passengers from Lamma Island to Victoria Harbor to watch a major fireworks display. (October 1 is China's National Day, marking the founding of the People's Republic of China.) Witnesses say about 10 minutes into the trip, the boat was rammed from the side by another boat traveling at high speed and sank "within 10 minutes." A chaotic scene followed as many families were separated in the darkness and most of the passengers were not wearing life jackets.

The ferry that sank was operated by Hong Kong Electric Company, which has already offered about $25,000 in compensation to the families who lost loved ones. About 100 people were on the second boat, which was heavily damaged, but made it safely back to port. 

The waters around Hong Kong and Lamma Island are some of the busiest in the world, but are also generally among the safest. Ferries are a common mode of transportation, but significant accidents are quite rare. According to CNN, this is the deadeliest martiime incient since 1971, when 88 people died after a ferry to Macau capsized in a storm. This weekend also marked the start of the "Golden Week," when most of the nation's businesses close down and workers are given an extended holiday, leading to a big surge in travel.

UPDATE: Hong Kong police announced that three crew members from each of the boats involved in the collision have been arrested, but have not said how they might have been at fault in the crash. The investigation is still ongoing.