fall apart

lose one''s emotional or mental composure

• “She fell apart when her only child died”

go to pieces

• “The lawn mower finally broke”
• “The gears wore out”
• “The old chair finally fell apart completely”

break or fall apart into fragments

• “The cookies crumbled”
• “The Sphinx is crumbling”

become separated into pieces or fragments

• “The figurine broke”
• “The freshly baked loaf fell apart”