collapsing
adj. B1 Intermediate US //kəˈɫæpsɪŋ// UK //kəlˈæpsɪŋ// col·laps·ing
adj. falling down or in because it is no longer strong enough to stay up. You use this to describe buildings, structures, or even arguments that are failing.
adj. in the process of falling down or in due to structural failure or loss of support. Typically used predicatively after linking verbs such as 'be' or 'become'.
The old wall is collapsing slowly.
The roof of the old barn is collapsing under the weight of the heavy snow.
As the foundation eroded, the historic bridge began collapsing, forcing engineers to close the road for emergency repairs.
Usage
Often used with 'in' (collapsing inwards) or 'down' (collapsing downwards).