In this case it was years of struggling with depression. Seems by the video shown he was very active and happy in the ministry. But the struggle was more than he could bear, and it hit everybody very hard. It's been a very sad time.
But I'm thinking maybe since they just had their regional they were on a particular high, some just returned from internationals. Seriously gung ho though...but I think it's for being in the social club, not any great witness they participate in.