Did I overreact when my daughter posted she didn't want to live anymore?

My daughter posted this on Facebook: " What happens when you don't want to live anymore? I'm about there and Its scary." I live 5 states away, and I tried to call and she wouldn't answer. She had came out here on vacation with her family, and left her two girls with us, and I hadn't heard from her since she got home on Sunday. I got her husband and told him what she had posted, and he said he had talked to her and she was upset, and wasn't picking him up from work, he had to find a way home. I told him I thought she needed to go to the emergency room, she's on depression meds. She then called me crying so loudly I couldn't understand what she was saying, but finally got that she thought he was lying and cheating on her. Then she said the police were at the door. They ended up having her call me back so they could talk to me about what was going on, and I told them about her threat. Worst part is my son-in-law is in the Navy, and his Captain brought him home. He had called 911 because of my concern. She had also called my sister, who heard her crying uncontrollably, and his mother. I got a text from him 4 hours later telling me I had overreacted and that I had put his career in jeopardy. She was just having a "cry" day. She called my sister back, but not me. I am not an idiot or an interfering mother. Because of another sister, I've dealt with mental health issues 35 years, but realize I can make a mistake. I need an objective opinion. What should I have done?