Stephen Curry #30 of the Golden State Warriors goes up for a shot on Pascal Siakam #43 of the Toronto Raptors at Chase Center on March 05, 2020 in San Francisco, California.

Disney's ESPN has long called itself the worldwide leader in sports. Now it will have to figure out what to do when there aren't any.

On what could be called Black Thursday for major sports leagues, Major League Baseball and the National Hockey League suspended play, following the National Basketball Association's lead on Wednesday. The National Collegiate Athletic Association followed by canceling March Madness, the annual men's and women's basketball tournaments that crown national champions, and all other winter and spring championships including the Frozen Four and the College World Series. The PGA Tour canceled the Players Championship after the first round and all subsequent tournaments until the Masters, which has also been postponed. Major League Soccer announced it is suspending play for 30 days.

That leaves all-sports networks -- particularly ESPN, which owns more rights to live games than any other media entity -- with several unprecedented problems.

Most urgently, ESPN will need to broadcast replacement programming for the games that won't be happening. In the near term, that includes NCAA conference championship games, NBA games and first-round NCAA women's basketball tournament games. Beyond that, ESPN has additional live college sports on ESPN+, its streaming service, and other linear networks including ESPN2, ESPNU and ESPN3.

Extended cancellations of live sports is not only bad for ESPN, but for the entire traditional pay-TV business.

With millions of Americans already leaving cable for streaming services each year, losing live sports for months may convince a surge of new defectors to try life without cable, which typically costs between $60 and $100 per month -- and some are likely not to return even when sports come back. Disney makes about $11 billion annually from ESPN and its sister networks, between getting about $9 per month for all the ESPN networks in affiliate fees and earning about $2.75 billion in yearly advertising, according to research firm LightShed. ESPN has about 81 million subscribers, LightShed estimates.