A protester broke his arm and leg after plunging at least 30 feet Sunday night while trying to exit a tree in an oak grove that the University of California at Berkeley plans to raze, the San Jose Mercury News reported.

Nathaniel Hill, 24, mistakenly thought he was connected to a cable when he stepped from his perch to see his father, who had stopped by to visit. Mr. Hill was among a group of protesters who are living in the trees in hopes of blocking the university from felling them to make way for a $125-million athletics center. He is not the first protester to take a tumble; a woman broke her wrists in a fall earlier this year.

The university has been sued over the planned tree-cutting, and a court decision is anticipated as early as this week.

Dan Mogulof, a university spokesman, said Mr. Hill’s accident was “very regrettable but to state the obvious, completely avoidable.” —Don Troop