A father and his 3-year-old son were injured Wednesday in Petaluma after their car rolled backward as they were getting out of it, the CHP said.

The incident happened about 10:40 a.m. at a plant nursery on Emerald Drive, Officer Jon Sloat said.

The father pulled his Ford Escape into the nursery and walked to a rear door to get his son, Sloat said.

But because the vehicle was not in park, it began to roll backward, catching the father behind an open door, Sloat said.

As the man fell to the ground, he grabbed his son, who was struck by the front wheel as a result, Sloat said.

The father was not run over, but suffered moderate injuries. Both were taken to Petaluma Valley Hospital. The child was flown to Oakland Children’s Hospital with moderate to major injuries.

An investigation is ongoing.

You can reach Staff Writer Paul Payne at 707-568-5312 or paul.payne@pressdemocrat.com. On Twitter @ppayne.