It was 5:30 a.m. Stores at the King of Prussia Mall would begin to open in the next half-hour. But the most determined of Black Friday shoppers — 300 of them — were already in line at Lululemon Athletica.

“The gates opened, and everybody flooded in," said Laura DiPietro, 27, who had arrived at the mall at 5 a.m. “Just grab what you see, hopefully in your size.”

Eight minutes past 6 a.m., the popular high-end apparel store where yoga pants could cost as much as $100 was filled. Buoyed by discounts of $20 or more, customers clutched armfuls of stretchy athleisure and pawed through the sales offerings. Wide-eyed Lululemon staffers squeezed through the crowd. As more people trickled in, store employees raced to restock shelves and racks with tank tops and leggings.

“Some people were grabbing piles,” said DiPietro, a fourth-grade teacher from Newtown Square, “then decided what they wanted.”

Late start at the Fashion District

Meanwhile, at Center City’s Fashion District, crowds were pretty sparse early Friday morning. After three years of construction, the mall re-opened in September, complete with confetti cannons and high hopes that it would revitalize its stretch of Market Street.

At 10:30, no stores were overwhelmed or crowded with customers, which surprised some store managers on the mall’s first big day for sales.

“It’s a new store, so it was kind of 50-50 whether or not it was going to be really busy or not, especially with the state of the mall,” said Riley Kevra, manager at Pandora. And many stores — including brands like Kate Spade and DSW — haven’t opened yet.

On Friday morning, most of the mall’s customers were concentrated at Game Stop, H&M, Express, and Century 21. But by early evening things had picked up considerably and the mall was busy with shoppers.

Will Johnson, 42, from West Philadelphia, visited the mall Friday morning to enjoy time with his grandson. He said he did most of his shopping online after Thanksgiving dinner.

“I know for a fact that this will get a little crowded later today,” he added, “It’s early.”

Black Friday not what it used to be

The National Retail Federation, the largest retail trade organization in the world, has predicted that 114.6 million people will shop on Black Friday nationally, 39.6 million the next day, 33.3 million on Sunday, and 68.7 million on Cyber Monday.

The group’s estimates are marginally lower than last year, when it predicted 116.4 million people would turn out on Black Friday.

Increasingly, Black Friday is not what it used to be, as consumers do most of their shopping online. Retailers typically offer discounts starting in October with some waiting until Cyber Monday to serve up their best deals.

This year, for the first time, more than half (54%) the respondents in PricewaterhouseCoopers’ annual holiday-shopping survey said they plan to do their shopping online.

Consumers spent a record $4.2 billion online on Thanksgiving, up about 14% from last year, according to Adobe Analytics. About half of that was done on mobile devices. Adobe estimates online sales of $7.5 billion on Black Friday, and $9.4 billion on Cyber Monday.

Overall, the Retail Federation expects 4% growth in consumer spending this year, to roughly $730 billion, but cautions that tariffs and fears of an economic slowdown could mean that consumers shop less.

The Conference Board reported this week that consumer confidence declined for a fourth consecutive month in November.

Teens and kids are big customers

For the first time since 2013, this year’s holiday shopping season — the window between Thanksgiving and Christmas — is shorter than usual by six days. For some, that has magnified the pressure to prepare, making Black Friday a race of economy and efficiency that requires a regimen.

“We get up at 4:30 and then get ready and come out at 5,” said Donna Monaco, 56, of West Chester, who has had a tradition of Black Friday shopping with her family for the last five years. “We go to Wawa and Dunkin’ — some of us like Wawa coffee, some of us like Dunkin’ coffee — and then we come here, and we have our whole day planned out.”

The family eats all three meals at restaurants on Black Friday. They visit north of 20 stores in Pennsylvania and Delaware. Around noon, they’ll make a quick stop to drop off their shopping bags at home, then head back out to the stores until late evening.

It’s a familiar sight on Black Friday — often grandmothers, mothers, and daughters who brave the predawn chill for prime choice of bargains. Men, too, have taken to Black Friday shopping. But increasingly, the day has attracted another crowd: kids on their own.

Ava Krouse, 17, showed up at 6 a.m. to go shopping with family friend Grace Crescitelli, 14. The two drew up a list of stores they wanted to visit, makeup and clothing stores among them. They planned to accomplish their holiday shopping over the weekend.

Two other teens showed up even earlier.

Best friends Briley Strine and Isabelle Hanlon, 16, were already at the mall at 5:20 a.m., 40 minutes before any stores opened. They ordered Starbucks and then waited, mapping out where to go — Urban Outfitters, Free People, Anthropologie, Sephora.

“We might go crazy, look at Louis Vuitton,” said Hanlon, a student at Archmere Academy in Claymont, Del. “Feel a little bougie for a second.”

Staff writer Jesenia de Moya Correa contributed to this article.