HARRIS COUNTY, Texas -- Two adults were killed and two children injured in a head-on crash near the Grand Parkway.

The vehicles crashed around 6:54 p.m. off FM 529 and Peek Road in northwest Harris County.

The children, a boy and a girl, were taken by Life Flight to Memorial Hermann Hospital in unknonw conditions.

The driver of one of the vehicles was detained at Memorial Hermann Hospital in Katy.

Investigators are working to determine what caused the crash.