Did a Tornado Cause the Yangtze River Boat Disaster?

As rescue efforts to save passengers and crew trapped aboard a capsized Yangtze River vessel, it's increasingly clear that the cause was at least in part related to the inclement weather at the time.
The passenger boat that capsized Monday night with at least 456 people on board encountered fierce thunderstorm-related winds, and possibly a tornado.
The storms it ran into were not unusual for the area at this time of year. They're comparable to what occurs in the Midwest U.S. each spring with towering clouds up to 55,000 feet in height dumping large amounts of rainfall and unleashing damaging wind gusts underneath them. The China Meteorological Administration has said that winds were close to hurricane force of 74 miles per hour.