I dealt with this not too long ago when I separated from my husband. He was telling my friends he was suicidal, he has had issues in the past and been hospitalized for severe depression. I was feeling very controlled by this, especially since I have a cousin whose husband did commit suicide seven or eight years ago.
I got some very good advice here at SR.
It may be that the first attempt and anything he says to you that indicates he is suicidal is an attempt to coerce or control you. What people here suggested, and what worked for me, was:
a) I suggested to my friends that he was calling that they were not capable of dealing with a suicidal person and that if he contacted them and told them he wanted to kill himself that they should contact 911.
b) I had a brief conversation with him where I let him know that *I* was not equipped to deal with suicidal thoughts or behavior and that if he told me he was suicidal I would take it seriously and call 911 on him.
Very quickly the threats of suicide dried up. Fortunately he has done some good things by getting into counseling and seeing a new psychiatrist and he is getting the help he needs.
Your husband may or may not kill himself, you have no control over it and you do not have to feel guilty for the choices he makes. I would say that not going over to his house is not a bad idea. My cousin's oldest son was with her when she found her husband, he was only 9 at the time and it was awful. He's in high school now and not surprisingly, he wants to become a psychologist or psychiatrist.