SAN FRANCISCO: What would happen if Facebook and some of its apps — such as Instagram and WhatsApp — were to all go down at about the same time? And then stay intermittently out for hours?

On Wednesday, people around the world found out when all three services experienced interruptions throughout the day.

The problems began around 11am Eastern Time and affected users in countries including the United States, Japan, Australia and Mexico, according to DownDetector, an analytics service that calls itself a weather report for the internet.

On Instagram, profiles refused to load. Some Facebook users logged on to empty news feeds, while others could see their friends’ updates but couldn’t like them. And WhatsApp users had trouble sending and receiving messages.

Facebook’s chief executive, Mark Zuckerberg, recently announced a push to bring all of his apps closer together, uniting direct messages across different services. The service interruptions highlighted the potential risks of a consolidated social media giant, as users flitted from one lonely social feed to the next, searching fruitlessly for updates. Even Facebook’s own bug report platform — in which it discloses what services are down — was offline. So the company used one of the only major social media platforms it doesn’t own, Twitter, to announce updates. Since Facebook and its apps have so many users — around 2.7 billion around the world — the venting was, understandably, heightened. Some people expressed grief at the apps being unavailable. Others said they were fleeing — where else? — to Twitter.