Firefighters in the Blue Mountains say four people are lucky to have escaped serious injuries after a two-car crash.

It happened on Grey Road 2 and Grey Road 40 around 11 a.m. on Monday.

A mother, father, and their 3-year-old son were in the dark-coloured vehicle. There was a sole occupant in the white pick-up truck.

All four people were taken to hospital as a precaution, and they’re all expected to be okay.

Deputy fire chief, AJ Lake, says the crash is believed to have been caused by one of the drivers running a stop sign.

Air bags were deployed in both vehicles.