NASA astronauts Scott and Mark Kelly both tweeted messages of mourning over the terrorist attacks in Brussels, Belgium.
The bombings, carried out yesterday (March 22) at the Brussels airport and one of the city's subway stations, left 31 people dead and 270 injured, The New York Times reported.
Scott Kelly, who recently returned from a yearlong mission in space and will retire on April 1, tweeted a serene photo of the Earth taken from space, and said, "This perspective of Earth makes violence on its own people unimaginable. Thoughts with #Brussels."
Mark Kelly, also a former NASA astronaut and Scott's identical twin brother, tweeted a message of condolence, in which he wrote, "The world stands with the people of Brussels & Europe in the face of this evil."