Facebook Inc. suffered a devastating outage that shut out many of its 2.7 billion global users, idled some of the company’s employees and prompted a public apology from the chief technology officer.

The company’s family of social media apps, including the main social network, photo-sharing app Instagram and messaging service WhatsApp, began to return online for some users about 5:45 p.m. New York time, more than six hours after the incident began. It was one of the longest failures in recent memory. Downdetector, which monitors internet problems, said the Facebook outage was the largest it had seen, with more than 10.6 million reports worldwide.

"To everyone who was affected by the outages on our platforms today: we’re sorry,” Facebook said in a statement. "We know billions of people and businesses around the world depend on our products and services to stay connected. We appreciate your patience as we come back online.”