a quick thought and vague attempt to be kafkaesque
An Auto de Fe
One morning, God reveals to our protagonists, P and Q respectively, that they are each to die today. Each, understanding that this is the true word of God, go about doing whatever each would do under such circumstances.
The weather turns violent.
While walking home in the thunderstorm, P notices a man he has never met, Q, soaking wet and walking in the opposite direction. Charitably, P hands Q his umbrella. Q accepts and the two continue on their respective routes home while the storm rages on. P, soaked to the bone and freezing cold dies of hypothermia. Meanwhile, Q, who's newly acquired umbrella acts as a lightning rod, gets electrocuted and he too dies.
The simplest random act of kindness is often the deadliest.