CES, one of the world’s biggest technology conferences, will be a virtual event in January due to the coronavirus pandemic, a reversal from May when organizers said it would go on as a smaller gathering in Las Vegas.

The announcement Tuesday is another blow for Las Vegas which, like all other U.S. tourist destinations, is suffering as people stay home or vacation locally. More than 170,00 people attended the four-day show this year in January, before COVID-19 began to spread across the U.S.

The pandemic has disrupted major tech events everywhere.

Europe’s biggest consumer electronics trade fair, Germany’s IFA, usually runs for six days and drew nearly a quarter million people last year. This year, it's half that duration and there will be no public access to the event in September. Web Summit, a glitzy event in Portugal that features high profile tech CEOs and celebrities, will be online this time. Organizers aim to still hold the physical conference in Lisbon in December but won’t make any final decisions until early October.

Trade shows are a place where people network, try new gadgets or make a sale. But they're also big business onto themselves, accounting for $2.5 trillion in global spending, according to the Events Industry Council. Much of that is likely to be lost when events go online.

The Consumer Technology Association, which organizes CES, had said in May that it planned to go ahead and hold some events in Las Vegas next year, but the thinking changed as COVID-19 cases spiked around the world, making it impossible to hold an indoor event in January 2021, said CTA CEO Gary Shapiro.

There was also uncertainty over whether employees of big tech companies would be allowed to travel by then. Google, for example, said this week that its employees should work from home until at least July 2021.

The four-day digital version of the CES gadget show begins Jan. 6.

Kelvin Chan in London contributed to this story.