A girder of a gantry crane fell in Shanghai Hudong Shipyard at 7:55 am today, killing at least 10 workers and injuring other 26, eastday.com reported.
Officials estimated the number of casualty would rise to 35.
Nineteen pumpers were dispatched to clean out the spot.
An unidentified resident said he heard a blare when he got up and felt the room shaking for a few seconds.
The gantry crane is 130 meters high and has the sling capacity of 600 tons.
But it's only 20 meters high after the crane fell, according to eyewitnesses.
Hudong Shipyard, built in 1928, is one of the leading ship-making factories in the country.