There is a nearby Walmart Wu's father used to visit every two or three days. As long as it was open, the old couple would feel safe about making their purchases anytime.

"They were at first reluctant to take my advice to stock up on things and insisted that supplies were sufficient," Wu recalled.

Yet the situation became complicated as Wuhan took stricter measures to lock down residential communities and closed supermarkets. The city had previously suspended all public transport and outbound channels on Jan. 23.

Opening a food-delivery app on her phone, Wu could hardly find any convenience stores or greengrocers that were still open.

Her mother finally relaxed after Wu made a bulk order one day on a mobile app, with meat, vegetables and fruits costing more than 1,000 yuan (about 144 U.S. dollars).

"Some might think that I was unlucky to have left Tianjin to spend the Spring Festival holiday in Wuhan with my parents, but I don't think so," Wu said, noting that she was lucky to stay with them during this tough period since the old couple seldom use the Internet.

"Community workers have started to make food deliveries, helping us buy what we need," Wu said.

Zhang Xiaoxu (pseudonym) felt lucky too. The 25-year-old had been racking his brains to figure out how to buy food and finally got what he ordered -- one kilo of pork, a grass carp and a package of vegetables.

Some online orders he had previously made stopped delivering as logistics sites closed. Supermarkets only accepted group purchases.

"The minimum delivery price on mobile apps has been greatly raised and some of my favorite purchases were out of stock, like the Laoganma chili sauce," Zhang said. "So I later joined a shopping chat group founded by volunteers in the community."

Food prices were higher than usual, but Zhang remained optimistic, saying better expensive than unavailable.

He envied one of his neighbor who lives in an opposite building and has cultivated a small garden plot on the roof.

"I never thought much of the garden before," Zhang said. "But now, I am jealous of the guy who has it."

Like Zhang, 23-year-old Yang Xiaoxiao (pseudonym) has been bouncing around several chat groups for group purchases of groceries every morning -- the first item on her daily to-do list when she wakes up.

Buying food suddenly became a problem since her residential community was fully locked down and everyone stayed indoors.

Living outside the 3rd ring road in Wuhan, she had no choice but to order food supplies through group purchase, since most deliveries made on apps were out of range.

"I didn't want to miss any group purchase information in the chat groups," Yang said. "I have to go through all of them to get a good deal and make orders the first time around if the prices are acceptable."

Sometimes Yang had no choice but to buy a set package of goods, which often included items she did not want or need.

She mentioned an old man in her community who wanted to buy tissues but helplessly ordered a set package with sanitary towels in it.

"Fortunately, there's always one way or another for young ones like me to order what we need online," Yang said.

However, for the elderly who cannot use smartphones, things are rather more complicated.

"I hope the community and the volunteers can take good care of the seniors," Yang said.