Chiefs QB Aaron Murray -- Engagement Is Off ... Hot Reporter 'Moving On'

Stick a fork in 'em, 'cause the engagement between KC Chiefs QB Aaron Murray and smokin' hot news reporter Kacie McDonnell is over ... and it doesn't sound like there's any chance of a reconciliation.

Their love story became national news ... when she left her job (a great job) as a reporter in Philadelphia last year and moved to KC to be with Aaron who was drafted by the Chiefs.

Kacie got a job in news in Kansas City and everything seemed to be perfect ... until McDonnell made this shocking announcement:

"I’m really committed to being a part of this community for the time being. The engagement is off. I wish him the best, it’s best to part ways. I’m moving on with my life."

FYI -- Aaron's brother is Josh Murray who just broke off his engagement to former "Bachelorette" Andi Dorfman earlier this month.

Happy almost Valentine's Day everyone!