Global markets took a steep drop Monday as investors grew increasingly anxious about the swift spread of the coronavirus beyond China’s borders.

The Dow Jones industrial average fell 454 points, or 1.6 percent. The Standard & Poor’s 500 and Nasdaq also slid significantly, 1.6 percent and 1.9 percent, respectively.

Travel-related companies were hit particularly hard. Shares of American Airlines lost 5.5 percent and Delta fell 3.4 percent. Wynn Resorts, which has a large footprint in Macao, fell 8.1 percent. Las Vegas Sands fell 6.7 percent. Luckin Coffee, a company based in China that manages more than 4,000 locations, saw its stock price fall 9 percent.

“If the current outbreak turns into a pandemic that significantly disrupts global commerce, the impact would be bad news for the global economy and corporate earnings,” said Ed Yardeni, president of Yardeni Research.

Monday’s losses pushed the Dow Jones Industrial Average below where it started 2020. But the stock market is still up markedly from where it was one year ago.

Even as China has moved to sequester its residents during one of the year’s busiest travel seasons — Beijing has extended the quarantine to more than 50 million people — the mayor whose city, Wuhan, is the epicenter of the outbreak said 5 million people had managed to leave.

So far, the coronavirus has infected at least 2,800 people in China and killed 82. Health officials say the virus has the potential to be more deadly than the 2002-2003 SARS outbreak, which killed nearly 800 people and infected more than 8,000 others.

Separate from the public health concerns, the economic impact of coronavirus “will be significant,” wrote Michael Farr, president of Farr, Miller & Washington, a D.C. investment firm, in an analyst note. Travel in Asia has already slowed dramatically. And there’s concern that supply chains could be disrupted if, for example, the delivery of auto parts or manufacturing grinds to a halt.

“In the global economic fabric, China will cause a measurable slowdown,” Farr said, cautioning that it’s still too early to determine the virus’s precise impact on global GDP.

There have been five confirmed cases in the United States: two in California and one each in Washington state, Arizona and Illinois. Infections have also been confirmed in Canada, France, South Korea, Japan, Nepal, Thailand, Singapore, Vietnam and Taiwan.

Brad McMillan, chief investment officer at Commonwealth Financial Network, wrote in an analyst note that SARS, or severe acute respiratory syndrome, hit growth in China hard before passing relatively quickly. Most of the damage came from consumers staying in and not spending, so growth picked up once shoppers’ routines returned to normal.

But even though the Chinese economy, which depends heavily on consumer spending, could suffer, the United States is likely to avoid a major blow.

“Over the course of a year, SARS was a nonissue for U.S. investors,” McMillan wrote. “Even if this new disease proves to be much worse than it looks at the moment, here in the U.S. the damage will be limited — and should pass quickly.”

The outbreak, which comes just after Washington and Beijing signed a partial trade deal, also creates uncertainty for businesses that manufacture and source materials in China. Nike shares fell 1.8 percent, and Apple’s stock slumped 2.9 percent.

Apple could still find cover in the near-term. Many Chinese customers already bought iPhones or AirPods in the run up to Lunar New Year, wrote Dan Ives, an analyst with Wedbush Securities, suggesting a “strong December and January [are] likely already in the books.”

“While China is a major part of our bull thesis and growth story of Apple for the coming 12 to 18 months, we do not view the impact of this virus epidemic as changing the numbers,” Ives wrote.

European markets were all in the red Monday, with the FTSE 100 and the DAX trading down more than 2 percent. Many Asian markets were closed for the Lunar New Year holiday, but the Japanese Nikkei 225 also lost ground.

Brent crude, the global benchmark, was trading down 3.4 percent, and gold, a safe haven for investors in times of turmoil, was up 0.6 percent.

Meanwhile, Boeing shares fell 2 percent Monday amid conflicting reports of a plane crash in Taliban-controlled territory in central Afghanistan. It’s not clear what caused the crash or who operated the aircraft. Initial reports said it was a passenger jet, but video footage posted by a Taliban-linked account appeared to show a U.S. Air Force plane.