Dozens of major websites — including The New York Times, CNN, Reddit, Spotify, Twitch, GitHub, gov.uk, Hulu, HBO Max, PayPal, Vimeo, Shopify — were down Tuesday morning during an apparent massive internet outage.

What's happening: The cause of the outage was not immediately clear. Fastly, a popular content delivery network (CDN), confirmed it was experiencing an outage on its website, TechCrunch notes.

• Fastly helps websites with significant amounts of traffic distribute user flow across many smaller, distributed networks.
• When a CDN goes down, it often takes many sites with it, but it's usually not too hard to fix.

This story is developing. Please check back for updates.