It is the weight of the edifice exceeding its material strength, with the additional stresses of the magma inflating the internal regions of the edifice, that can generate the initial cracking around a developing volcanic summit. Additionally, tectonic activity such as normal faulting is also commonly associated with formation of rifts along volcanic flanks.
The collapse of an edifice happens when its weight exceeds its material limits, and this is furthered by magma expanding within the internal regions of the structure, causing initial cracking at a developing volcanic summit. Moreover, tectonic activity such as normal faulting is also frequently connected to the formation of rifts along volcanic flanks.