Brussels was rocked by three deadly explosions Tuesday morning, starting with two blasts at the Belgian capital's airport around 8 a.m. local time (3 p.m. EDT). The Islamic State has claimed responsibility for the attacks.

Here's an animated heat map The Washington Post created to help illustrate how news of the tragedy spread across Twitter. It shows global tweets featuring location information that included the word "Brussels" from 3 a.m. to 11 a.m. EDT on Tuesday morning. Although only a small fraction of tweets are geotagged, it helps show just how much online attention the attacks received.

As you can tell from the graphic, Europe was talking about the attacks from the very start, but global online interest peaked between 7 a.m. and 8 a.m. EDT and then died down some.

Belgian officials urged people to turn to social media to check on loved ones because of strain on the local mobile phone network in the wake of the attack. The #Brussels hashtag trended worldwide on Twitter, and Belgians and other Europeans started tweeting offers of assistance to those affected by the attacks with the hashtag "#ikwilhelpen" or "I want to help."