Sylvain Lefevre/Getty Images
Twitter users are using the hashtags #OpenHouse and #PorteOuverte to signal that they have space to take people in after a series of attacks in the Belgian capital killed dozens and brought the entire city to a standstill.
The hashtag #IkWilHelpen ("I want to help") is also being used by Belgians to coordinate offers and requests for transport and other aid.
A series of explosions at Zavantem airport and Maelbeek metro station have killed more than two dozen people and injured scores more. All public transport has been shut down in the city, flights are being diverted, and trains are being cancelled.
So Belgians are stepping up and trying to help people left without anywhere to go. People with homes in the city are using the two hashtags (#OpenHouse and #PorteOuverte) to indicate their availability.
People offering - or looking for - transportation and other forms of help are also using the hashag #IkWilHelpen to coordinate.
A similar effort took place in Paris in November following a series of attacks in the French capital: Parisians used the hashtag #PorteOuverte to offer their homes to those stranded by the deadly terror attacks.
And a word of advice: Don't use the hashtags unless you are actively offering aid, or seeking it, so as not to make it more difficult for people who are.