An oil exploration ship crashed into a barge and overturned near Chengdu, China, leaving 71 people missing and feared dead in the second major boat accident in southwestern Sichuan province in four days, reports said today. The Sichuan Daily said the Yunhang No. 24, a wooden vessel leased by the Sichuan Petroleum Administration, overturned Monday morning in the Yangtze River after colliding with a barge.