A man and three women were hospitalized Wednesday after a tree fell on them in Riverside Park, police said.

The group of local residents, between the ages 48 and 55, was lounging on the grass of the Upper West Side park near West 91st Street around 6:10 p.m. when they were struck by the falling timber.

Two of the women suffered head trauma, while a third woman suffered head and arm injuries. The man injured his arm. All of the injuries were considered minor, according to police.

All four were transported to St. Luke’s Hospital in stable condition.

The Parks Department and ESU were on the scene to remove the fallen tree.