And there are countless more people whose acts of selflessness during the carnage may never come to light.
But today, one hero's name is ringing out across the globe. Social media is paying its own unique tribute to Diesel the fallen police dog, lighting up the hashtag #JeSuisDiesel or #JeSuisChien with images of pets paying homage.
The Belgian shepherd's job was to sniff out explosives. This week he found them in the Paris suburb of St. Denis.
#JeSuisChien and so sad... https://t.co/T3uzTAcSyQ
— JandB (@MahaloKona)
#JeSuisDiesel who died in line of duty https://t.co/frEddWN64j