Rescuers bow their heads as they pay tribute to a victim of the cruise disaster, June 6. [Photo/IC]

2. Was warning sent out to the ship?

According to CCTV, the Jianli Marine Bureau issued a grade-four rainstorm warning (the lowest intensity on a scale of 1 to 4) at 9:00 pm on June 1, half an hour before the Eastern Star capsized, with the cruise ship in the range of the warning signal.

But it remains unknown whether the crew members on the ship received the warning signal.

Li Jiang, the deputy head of Yangtse River Marine Bureau, said that the ship is equipped with VHF (very high frequency) radio which can receive warning signal.

But a professor of Wuhan University of Technology told thepaper.cn that VHF radio may dysfunction in some cases, such as "in heavy rainstorm or when the ship arrives at a place without base station around. And the Eastern Star was in a water area without any base station around."