The pilot left the cockpit at 10.30am, probably to go to the bathroom. His co-pilot Andreas Lubitz then locked him out, and set the altitude meter to 100ft, its lowest possible level. For 10 minutes Lubitz flew the plane alone, while other crew members banged frantically on the cockpit door. Finally he crashed into a French mountain, killing all 150 people on Germanwings flight 4U9525 from Barcelona to Düsseldorf. We now know that Lubitz had done web searches for suicide, and for security of cockpit doors. Lufthansa, the parent company of Germanwings, had twice refused to renew his medical certificate due to depression.

Humans have always killed humans, yet the Lubitz story is a peculiarly modern nightmare. The first anniversary of the Germanwings crash, on March 24, reminds us that the biggest fear for westerners now is the human factor: murder and war, everything from Lubitz to Isis to Trump. That’s not because humans have become deadlier than before. Rather, it’s because the other eternal causes of premature death — disease and accident — have become less deadly.

Almost anybody’s family history is riddled with infectious disease, accident and violence. In the early 1900s my great-grandparents lost two children to scarlet fever in Manchester. Another great-grandfather was killed in a train accident, and a great-aunt died after choking on a fishbone. My grandfather was murdered at home in Johannesburg in 1963.