LostBrerMatt - There was something that Ben had said regarding the statue but I can't remember.
However, regarding the Statue, which most believe is partly the god of fertility, it makes sense that both incidents, women dying during pregnancy and the statue collapsing, would occur at the same time. I kinda knew it might be the case during the Season 5 finale, because up until that point, in 1977, women would live after giving birth...as Juliet witnessed. Logically, at this point, the conclusion is that The Incident is the only thing that would be the cause.
After the incident, excluding the purge, which wouldn't effect either issue, there is no indication of a possible cause.
The only thing I can think of would be the "sickness" Danielle talked about...but she, much like Claire, were able to give birth on the island. Similiar to what happened to Locke and Co., during the time jump flashes, it could've been an issue of both Claire and Danielle being already pregnant, but being on the island for a short period of time. That, allowed them to give birth, where as someone like Sun, as conception was done on the island and because of how long she had been on the island, which her case was similiar to the Others, would suffer the same fate as the Other women and die. Maybe the button pushing allowed for some women like Claire and Danielle to live, but people like Sun and the Other women, not to.
However, The Incident in one form or another happened in both timelines and I believe it not only caused the Statue to collapse but also in the present timeline, caused women on the island to die during pregnancy, etc, etc.
Regarding the present timeline.
If you remember back in the Season 2 finale, the choas that was caused when Desmond didn't push the button. I'm thinking it was 5-10x that, because it was free flowing, and because Dharma had no failsafe or protection installed yet...not realizing what would occur.... like it did when Desmond was able to stop it which was after the fact, and maybe much like what we saw at the end of Season 2, with Desmond turning the failsafe, only a lot bigger, there was a massive release of electromagnetivity back in 1977.
There might have been a break or in between the chaos, Radzinsky and Co., along with Pierre, had to act quickly, and seal off the leak with cement, insert the failsafe and button...(like everything we saw when we first saw the Swan)....and Radzinsky was forced to stay down there to make sure the button was pushed.
Sideways timeline:
With the detonation of the bomb, ONTOP of the electromagnetivity, that pretty much atomized an entire layer of foundation that the island was on, causing an earthquake/complete surface disruption, ala Broken Arrow, caused the Statue to collapse, and then the island to sink.