It’s also good to pray when one hears an ambulance or fire engine. Kind of off-subject, but thought I would just throw it in. My little boy is trained well in this and often reminds me when I forget. We say a Hail Mary and then Jesus, Mary and Joseph, please help whoever is in trouble.
Just yesterday, one of the ladies in our parish suffered a heart attack in the middle of Divine Liturgy. We were all praying for her, obviously, even though the Liturgy still proceeded.