>>reporter: after basic training, vanessa was assigned to fort hood in killeen, texas. there she specialized in small arms and artillery repair. vanessa made friends, things went well, she received great feedback from superiors. on weekends she would make the three hour drive to visit her family in houston. but a few months in, her family noticed a change. >> [speaking spanish] >>reporter: gloria asked her daughter what was wrong. [speaking spanish] >>reporter: now, a year later, vanessa had gone off the family radar. as the days past, her silence nagged at myra. of course, she could just be busy with work. still, it wasn't like vanessa to disappear. the problem was, we are to look for her? >> for who it is one of the largest army installations in the world. >> >>reporter: jasmine caldwell reports four kcen tv on fort hood. >> it has 214,000 acres. there's about 65,000 soldiers, roughly. so it's a very, very large place. >>reporter: myra agonized. the place was so large, her sister could be forgotten easily. and she didn't like what she heard when she spoke with one of