A parcel delivery man in Hunan province died at work late Monday during the peak delivery period for the Single's Day shopping festival.

The 39-year-old, surnamed Yin, was driving through a busy street in Zhuzhou city when he parked his tricycle, sat on the ground and passed out after telling passers-by that he was "exhausted".

He was pronounced dead on arrival at Zhuzhou People's Hospital.

Online sales volume exceeded 177 billion yuan ($25 billion) on Single's Day this year, which meant more than a billion parcels had to be delivered in the following weeks, according to a report from data provider Syntun.

"Hard as it is to improve online sales volume, it is still achievable, but the 600 million, even up to 700 million parcels that will be delivered poses a great challenge," said Jack Ma, chairman of Alibaba Group, in a speech at this year's shopping day gala.

Alibaba Group created the Single's Day shopping festival, which falls on Nov 11, in 2009.

One of Yin's colleagues described him as hardworking, and willing to be on duty from dawn to dusk.

Although an autopsy has not been conducted, Yin's wife believes her husband died of exhaustion.

"My husband has never had any health checks in the past, but he was working so hard lately and died on duty. So I think exhaustion is the one of the main causes of death," Yin's wife was quoted as saying by Zhuzhou Evening News.

Feng Jianyuan, 46, who has been working in the industry for five years, said his workload tripled during the Single's Day delivery period, adding that he often worked nonstop from 6 am until the midnight in November.

Li Lei contributed to this story