ichidan verb, transitive verb
let die; allow to die
Literal causative meaning: to let someone die, either by inaction or by not preventing death. Often implies a degree of responsibility or neglect.
彼は怪我人をそのまま死なせてしまった。
He ended up letting the injured person die.
そんなことをしたら、犬を死なせる
If you do that, you'll end up letting the dog die.
ichidan verb, transitive verb
Euphemistic use: to cause someone's death, often in a context where direct words like 殺す are avoided. Can sound softer or more indirect.
あの事故で三人も死なせてしまった。
That accident ended up killing three people.
彼は敵を一人死なせた。
He killed one of the enemies.