Problem implementing closing functionality on React component

Hello everyone.

First of all, great community. You guys have all been very inspirational and have contributed immeasurably to my successes as a developer.

I’m developing an app to practice my React skills (still very much WiP), available here.

I am having problems implementing a solution whereby I can click on the X in the corner and remove the comments deck. I don’t know how to get this to be reflected in the state.

Thank you for your help.