Question about Saudi Law regarding women, does anyone know what happens if..?

A woman is without a male guardian, or without any one willing to take guardianship over her? Say some extreme circumstance (only child, mass tragedy kills off family and she is the only survivor) leaves a woman without a male family member and she has no husband what happens to her? If no relative can be located who decides her fate? With all the news about Saudi Arabia the last few days, it got me wondering what if.