Jittery residents — a few wearing masks and rubber gloves — crowded grocery stores and big-box warehouses Friday hoping to stock up on supplies and ride out an unprecedented call to help stop, or at least slow, the spread of the deadly novel coronavirus.

Many people, under orders to work from home as a safety precaution, piled into stores where there was more than a little panic-buying and hoarding, a few fights over parking spaces and food. One woman said she left a store in tears after watching people battle over frozen food.

Some bought stuff they thought they might need and some — triggered by the sight of empty shelves and dairy cases — admitted buying stuff they might not need at all. The new pandemic-driven shopping calculus meant skipping fresh produce and instead grabbing canned goods, items from the freezer case and other nonperishable items. Toilet paper vanished from local grocery stores and appeared to be in short supply online, too.

“I just got the last bag of flour at Safeway,” Tara Mullin, 29, a data analyst for a nonprofit organization, said as she left the store in the District. She said she planned to follow through on plans to celebrate St. Patrick’s Day with a batch of cookies.

The number of reported cases of the coronavirus in the region hovered around 59 Friday evening, according to a Washington Post analysis. Reported cases in Virginia nearly doubled overnight, rising to 30. Maryland has reported 18 cases, and the District has reported 11 cases.

Concerns over the spread of virus have led many jurisdictions to cancel events where large numbers of people might gather. Businesses have asked employees to work from home. Schools have closed, some for up to a month. And universities have sent students home, unsure of when they might be able to return. The sense of unease and the realization that some people might be stuck in their homes for at least a couple weeks had many flocking to stores, hoping to get cleaning supplies and any non-perishable foods they could find.

The scene at Costco, located on South Dakota Avenue in the District, was chaotic. Motorists bickered and jockeyed for empty parking spots as car alarms wailed and shopping carts rattled by. Lines of people snaked out the door and down the side of the building, including a woman with a 2-year-old who swabbed her shopping cart with Lysol disinfectant. For a time, the store was so crowded that entry was temporarily halted. Shoppers on the way out pushed carts laden with food, booze and bleach. Tom Cox of Brookland said vodka was a good hand sanitizer, after all.

Jacalyn Cox, 68, a yoga teacher from Brookland, said all the waiting in line among all those people added to her stress.

“I wish I hadn’t been in there,” said Cox, who was pushing a heavy cart loaded with pasta, paper towels and dog food into the parking lot. “I couldn’t wait to get outside and breathe. That’s a lot of exposure.”

Cox said this panic-buying spree seemed different than others. “I just think people are really afraid,” she said. “This is something we’ve never experienced before. … It’s scary.”

Ruth Hrubala and Kyle Johnson became friends while waiting on line Friday afternoon at the Trader Joe’s on 14th Street NW. The line — five hairpin turns around the shelves, some of which were cleaned out — took maybe an hour to get through.

“We’re making fun of this mayhem,” Hrubala, 50, said. “It’s crazy.”

“I didn’t stock up beforehand, and that clearly was a mistake,” Johnson, 24, said. “Now that everyone else has panicked, well, … we have to panic.” Johnson, who recently opened The Hollows coffee shop in Adams Morgan, and Hrubala, chief of staff for a business in Alexandria, said they have witnessed consumer mayhem in some stores. Flowers strewn on the ground, people gobbling down food in the stores without buying it, battling outside for parking spots and battling inside for whatever they could get their hands on.

“I went to Costco last night and people were fighting over things,” Johnson said. “I tried to get one onion last night and couldn’t get a single one. This is the first time I’ve been able to get bananas.”

Similar scenes left Hrubala feeling distraught.

“Yesterday was dire for me. I left this store actually in tears,” said Hrubala, who also had seen people at their worst in the past few days.

“It just felt so strange for shelves to be empty and people fighting over food,” she said. “People were grabbing food out of people’s hands at the frozen section.”

The Giant Co., which operates 186 stores in Maryland, Virginia and other states, reported overwhelming demand for many household staples, including cleaning supplies.

“We are focused on getting back in stock as soon as possible,” Giant spokeswoman Ashley Flower said in an email. “We apologize to our customers for this inconvenience.”

Shortages hit Hrubala, who was at Trader Joe’s buying for friends and for her dog. But the dog — thanks to a run on ground beef — might have to cope with a change in diet.

“I’m trying to keep a level head,” Hrubala said. “Personally, I don’t think there’s this much need for panic.”