Same thing happened to my neighbor. There is a gap between the tar road and rear wall of the extended kitchen. Must be the result of soil movement.

During his 14 years stay, twice the floor tiles in ground floor exploded 💥💥. From kitchen to living room!
He only found out the gap appears after the tiles exploded ! He seldom survey back side of his house bcos rear door can't open ---> door frame tilted.

Twice he covered the gap with cement to prevent water goes in underneath his house. Contractor suspect hot weather causing hot air vaporation underground + soil movement --> tiles exploded!