Career-Driven Decision at the Cost of a Personal Relationship?

I jeopardized a decade-long friendship because I pulled out of a project with this friend and chose to take an opportunity that would benefit my career. This was a passion project and very close to their hearts. They have every right to be angry with me, disappointed in me, but this other opportunity is already helping me build my career in an exceptional way. It's such a hard question and it's such a personal question and it so depends on the situation.