The ship had been traveling from Nanjing, capital of east China's Jiangsu Province, to Chongqing city in the southwest.
As rescue workers scramble to find survivors and remains, what do we know about the tragedy so far?
At the moment, there is just speculation about the cause of the incident. The ship capsized around 9:30 p.m.
June 1, during a storm in the section of the river that flows through Hubei's Jianli County, authorities said.
The captain and the chief engineer, who were among the at least 14 survivors of the incident, claimed that the ship sank after being caught in a "longjuanfeng" -- meaning cyclone or tornado -- reported the local Xinhua news agency.
The captain and the chief engineer said
the ship capsized "within one or two minutes" of being trapped in extreme weather conditions, the China Daily newspaper reported. Wang Yangsheng, a senior official with the Yueyang Maritime Rescue Center, said
that the incident happened "so fast that the captain did not even have the time to send out a distress signal," according to the newspaper.
However, Zhang Zuqiang, a senior official with the China Meteorological Administration, told Beijing News
that he wasn't sure that there had been a cyclone, but that it had been raining heavily at the time.
The ship was not found to be overloaded and had enough life vests on board, according to the South China Morning Post (SCMP
More details are set to emerge as the captain and chief engineer are taken into custody and questioned by police, according to state media.
Who is still missing?
The SCMP also reported that officials believe five people may be trapped inside the ship's upturned hull.
"Rescuers knocked on the ship and received responses," the China Daily reported.
One elderly passenger was rescued, with state TV showing footage of rescuers cutting through the hull with an angle grinder.
Authorities say most of the passengers on board were senior citizens. Xinhua reported
that of the 456 on board, 405 were passengers, five travel agency workers and 46 crew. State media had earlier reported that 458 people were on board.
that relatives of the missing passengers have been gathering outside the Xiehe Travel agency in Shanghai, which has closed its doors with a note saying that members of its staff are busy with the rescue efforts.
How difficult is it to reach the scene?
The sunken ship is about 3 kilometers (1.9 miles) from the shore, where the river is around 15 meters (50 feet) deep, China's state-run broadcaster CCTV reported.
More than 3,000 rescue workers, including 2,100 soldiers, policemen and more than 1,000 civilians were involved in the salvage operation along with approximately 150 boats, the China Daily reported. But the rescue efforts are hampered by strong winds and heavy rain. Seven people swam to shore to alert the police at the time of the incident, it said.
What do we know about the Eastern Star?
The cruise ship is one of five luxury vessels
operated by the state-owned Chongqing Wanzhou Dongfang Shipping Company. The vessel is 76 meters long (249 feet) and has been in service for nearly 20 years with the capacity for 534 passengers, the China Daily said.
According to Quartz,
passengers paid 998 yuan ($161) for a 13-day cruise through eight provinces along the Yangtze River, as well as the Three Gorges Dam
-- a large scale hydroelectric project.
What do we know about the Yangtze River?
According to the World Wildlife Fund, the Yangtze River is the world's third longest river,
running for 3,900 miles from the vast Tibetan Plateau to the estuary of the East China Sea near Shanghai.
It says the Yangtze River Basin covers nearly 448 million acres -- more than four times the size of California. Large scale economic growth, industrial and domestic developments have caused the river to become increasingly polluted over the years.
This also isn't the first time that lives have been lost in the Yangtze River. In January, at least 21 people died
after a survey tugboat sank on the lower reaches of the river.
How can we learn about the fate of family and friends?
A local travel agency has published an emergency call number: +86 13983654321.
The Yangtze River navigation administration telephone number is: +86 (0) 27 82418021.