Crossword puzzle clue "building at a kid's party briefly"

Building at a kid's party, briefly

It's probably the biggest party ever for a kid. It's like the biggest party before college. It's what makes a man a man.

Basic building block of basic building blocks

Building block of a building block

___ Building, company headquarters erected in 1908 in New York City, at the time the tallest building in the world

Part of a kid's building set

Kid's building block

Kid going nuts with building blocks?