What’s a good response for my friend who’s other friend is currently feeling suicidal

I'm so sorry to hear that your friend is feeling this way. It is important for them to seek professional help as soon as possible. Maybe you can encourage them to talk to a counselor or therapist, or even reach out to a crisis hotline for immediate support. Let them know that they are not alone and that there are people who care about them and want to help. It's important to take all talk of suicide seriously and to prioritize their safety and well-being above all else.