Should i look for him?

3 years ago my X whom I was married to for 15 years, knew 20 years, separated from for 6 years (total of knowing him 26 years) went missing. This was not the first time, he has a gambling problem. Very young when we meet, married, two children, a - l o n g - story... too long and personal to put on here. However the first time he went missing, he was running form his lies, debts etc.. my kids where young, I did nt see it coming, I thought he was doing okay. Bang!! a couple of weeks before Christmas my world and my kids fell apart. I looked for him, I went through hell and back, questioned by police, threatened by people he owed money too etc. etc. etc.. Anyway he came back, I tried to help him get well, he did nt try, it ended. He remarried very quickly, two other kids with someone else, kept in touch with our children on and off. Three years ago he said he was going to New Zealand for work, this was out of the blue, 24 hours notice. He promised our children, then teenagers of 13 and 16 he would keep in touch, left a number and that was it. We have never heard another word. My last words to him were, please do not hurt the children again!! Anyway I felt so angry and hurt that this had happen "again" even tho this time we were not married and so on, but still. I did not try to find out what had happened, tired of the whole thing. However for my kids sake I often wonder if I should, to bring closer for them. Part of me thinks he may not be alive, but I do not know? My kids now 19 and 16 both have different attitudes, the older one is angry and says he never wants to see him again, the younger one is just hurt and I think worries if he is alive. When they were small up to the ages of 10 and 7 (the age they were when we separated) they never saw him fall home drunk, or do anything other then behave in a normal way, he was a master lire and could charm the birds off the trees. He played with them and read to them at night, so it really was a shock to them when he went missing. This is the gambling addiction, they lead two lives, and begin to believe their own lies, they become very mentally unwell eventually, and dangerous to both themselves and those around them. It has one of the highest suicide rates of addictions. I have very much moved on with my life, in a new relationship, working, busy and enjoying life without all the drama and lies. However I would like some closer here, I feel myself and my kids deserve some truth and to know what happened. His family have disowned him and we don't keep contact. What would you do?? please I would like to hear some empathic answers. Thanks. :)