What would you do?... not an easy question.?

let’s say you were in charge of protecting a group of children in a village and one day a barbaric tribe declared they would kill all those not born into their tribe and they attacked your village, mercilessly slaughtering every man woman and child in their path but you found a safe place to hide that they wouldn’t think to look. So you hide yourself and all the children there and as everyone outside begins screaming as they are hacked up it causes one of the infants in your care to begin crying. You know that if the infant continues crying they will find and kill everyone, you now have the choice to either smother the infant and save the rest of the children; or risk the barbarians finding and killing everyone, which is the morally right choice and why?