I never expected something like this would happen.
Please calm down and think carefully about what's taken place.
"Hey, do you want to kiss me?" "Absolutely no way would I ever want to kiss you in a million years. That would never happen even if heaven and earth were turned upside down."
You know that 起きる means "to wake up." This word, however, means to occur. Think of it this way. When an action "wakes up" in a way it is occurring as well. That's why this word means to occur. Just imagine a core (こる) of uranium just occurring out of nowhere to help you to remember this word.
The reading is the same as what you learned with the kanji and the same as 起きる too, meaning you should be able to put together the reading on your own.