The Belgian Crisis Center also recommended that those outside Belgium try to reach people "through social media first."
But even while recommending online methods to communicate, the Crisis Center advised against streaming audio or video to avoid overloading the local Internet. The major Belgian broadband provider Telenet announced that its WiFi hotspots across the country would be free for 24 hours but warned that the influx of users might lead to congestion on its network.
Facebook also has activated the Safety Check feature for users in Brussels. The feature allows people in the area of a disaster to confirm that they are okay. The company first turned on Safety Check after the Paris attacks late last year, when about 4.1 million people used it in the first 24 hours after the coordinated assault.