Insufficient safety measures coupled with the harsh climate and road conditions in Yushu, a quake-stricken plateau area in Northwest China's Qinghai province, have caused an increasing number of accidents involving volunteers over the past two months.

The latest accident happened on Oct 27 when a car carrying clothing and other winter necessities to primary school students in Yushu turned over along a 148-meter-high hillside, leaving three dead and two seriously injured.

Three of the volunteers were staff members of an educational enterprise named Family Box in Beijing. The other two were local Tibetans.

Andy Tsang, 35, the chief executive officer of Family Box, lost his life in the accident.

"The winter is coming. We should prepare goods and materials as soon as possible for the children so they can have a warm winter," Tsang, from Hong Kong, was quoted by his colleagues as saying at a meeting in early October.

Wang Rui, one of the survivors, recalled that Tsang took over driving as their local guide had driven for 10 hours. However, the car lost control at a sharp turn, which was worsened by the slippery road after a snowfall, the Beijing News reported on Wednesday.

"He is one of the most kind-hearted men in heaven, and we will continue on with what he left and do it well," Tsang's wife was quoted as saying.

Wang, who was sitting in the back of the off-road vehicle, was saved by a local herdsman. She suffered a rib fracture and needed seven stitches in her head.

Urgyen Chosang, a Tibetan in the car, suffered a concussion and still remains in critical condition.

The winter goods were later delivered to the two schools as Tsang's wife distributed them to the children on Monday, according to another report by the Beijing Times.

A similar accident occurred in Yushu this September, claiming the life of a mainland employee of Oxfam Hong Kong, a poverty-relief NGO, when the car turned over as the driver tried to avoid a bird.

"Operating centers of poverty relief and aid work are usually located in remote mountain areas or plateaus, so danger is inevitable. But I never expected it would happen in such an extreme way," Liao Hongtao, director of the Oxfam China Unit, wrote on the organization's blog.

"We have put all our efforts into raising donations and arranging the campaign as winter is drawing close in Yushu, yet did not prepare well for the personal safety of our volunteers," Li Jie, a public relations director of Family Box, told China Daily on Wednesday.

"The accident should raise public awareness of the safety of volunteers and we hope in the future individuals or groups (offering aid) to Yushu will prepare better," she added.