If he's threatening suicide, there is little you can do here as you probably aren't taught to handle these situations, like I am so don't try but listen to him if he wants to talk. Is this why he was thrown out of his home and how old is he? Theres a lot of details missing here for me to really help out here but pray for him and he should be alright here. And now he will have to figure things out or apologize to his Parents or whoever threw him out. Good luck
