A: It surprised me when George announced he would quit.

B: Indeed. When word came in that he wanted to look at another place, it was a gut punch for us. The company was counting on him to lead the summer marketing campaign.

Note: “Gut punch” literally refers to a punch to the gut (stomach). To punch is to thrust a blow with a clenched fist and the gut area is usually tender and soft. If we receive a punch to our stomach, we may lose our breath momentarily, to say the least. It could be much worse if the blow comes unexpectedly. Harry Houdini (1874-1926), the magician and escape artist, was believed by some to have died from, among other causes, an unexpected blow to the abdomen. The idiom is a metaphor for any attack that is strong and impactful.