The Shore (2005)

Hungering for some quality alone time with her new boyfriend, Ray, single mother Kaliope Harris leaves her young daughter, Anna, in the care of loving grandmother Mrs. Harris. An idyllic day at the beach turns to tragedy for the Harris family, however, when in the blink of an eye the precious young Anna seemingly disappears into the vast sand. While Mrs. Harris struggles to accept the startling disappearance, her enraged husband hounds the authorities to step up their search and Kaliope and Ray comb the beach in a desperate bid to retrace Anna's every step on that fateful and tragic day.