CHESTER, Mont. (AP) — A 911 call over the weekend about an Amtrak train that derailed in rural Montana, killing three people and injuring dozens of others, set off a chain reaction of help from residents in nearby towns. People jumped into action to get passengers off the train and care for those who were stunned and had suffered bumps, bruises and other less serious injuries. The regional response of volunteer emergency responders, firefighters, law enforcement, medical providers and regular citizens all working together to help embodied the spirit of a rural part of Montana near the Canadian border. Investigators still don’t know what caused the crash.