falling wall

huangyhg

falling wall
your best bet would be to hire a structural engineer to investigate the wall and what its function is within the structural system.  the shape, intensity, and cause of the bowing could then be determined and considered in regards to the safety of the wall.   
you don't mention if the wall is concrete or block or whether it is load bearing.
is it retaining anything?
a structural engineer may advise propping the floor above whilst the wall is replaced.  the props must be designed in such a manner that the loads are safely transferred to elements of sufficient capacity.
nb