Help my friend is depressed ?

Help Okai so my best friend I used to go out with him but we were so close we didn't want to ruin anything so his 6 year old sister died last Thursday and he shows no emotion I tried to cheer him up today je smiled for the first time I'n a week we were playing minecraft and I kept making him laugh and he spat out his drink I'n laughter and it went over his wrist band so he took them off and he had scars all over his wrists i didn't say anything but I think I should confront him about it ? And help him I'm the only one who he let's I'n his room