Studies show that women are the last to leave and the first to return. Being the last to leave, you are in the most dangerous position, and being the first to return, you are in the position where things are the least stable.
Studies also show that women are actually less visible than men. We are not thinking about them so much when we do search and rescue operations. You can take a look at this on YouTube, if you want to. The videos are there to show that in disasters like the one in Sri Lanka and a couple of other places there is a woman sitting on the roof and waving, and there is a man sitting on the roof and waving, and the helicopter picks up the man. That's why.