8-year-old Elizabeth Collins and 10-year-old Lyric Cook were last seen five days ago leaving their grandmother's house in Evansdale, Iowa. That's about two hours away from the Quad Cities, near Waterloo. Their bikes and a purse were found later near a lake.
Police say they have no reason to suspect foul play, but they are grilling the parents, and family members have taken lie detector tests.
Myers Lake is being drained, and divers plan to check the bottom to rule out the possibility that the girls drowned.