Police say two children and their parents are dead and a third child is in critical condition after their vehicle went into a suburban Phoenix lake.

Police spokesman Michael Pooley says emergency rescuers were called to Tempe Town Lake around 12:15 a.m. Sunday after bystanders saw the SUV enter the lake.

Three responding officers and one fisherman jumped in and pulled out the 27-year-old father, the 25-year-old mother, a 6-month-old girl and a 2-year-old boy.

Pooley says all four were taken to the hospital, where the parents and the 6-month old died. Police initially said the 2-year-old had died but now say he is in extremely critical condition.

Pooley says detectives realized a third child was missing.

Divers went to the submerged car and pulled out the body of a 3-year-old boy.

The cause of the crash is under investigation.