Onomatopoeia!

And in a headline, no less. Thank you, Birmingham News. I'm not sure which of your gifts I appreciate more: the knowledge that long-overdue repairs are finally coming to a neglected stretch of Interstate 59 or the nerdy, grammatical fulfillment of seeing "ka-thunk" in big, bold letters above a newspaper story.

Yeah, you're right: I am sure. Ka-thunk!