Please help my ex is threatening me

I just found out my ex cheated on me for the fourth time Ik I should’ve left after the first time but I just broke up with him and he’s threatening to commit suicide and he’s biking to a bridge and sent me a video of him biking near the edge. I alerted his family and friends but I don’t know where he is. He says the only way he won’t is if I take him back. I can’t live with that burden