The 27-year-old pilot and his 44-year-old passenger were hospitalized with serious chest and back injuries, police said.
Their names had not been released pending family notification.
Police credit the pilot for landing about 100 feet from the Indian Fields Elementary School in Dayton, and not hitting it, although it wasn't in session at the time.
Richard Mazur was heating up tar with propane gas on the roof of the school when he spotted the helicopter circling above, taking pictures.
"I said a joke: `Maybe the pictures (are) for immigration," said Mazur, a U.S. citizen originally from Poland. Suddenly, the chopper veered toward them and spun around.
"In a couple seconds, the copter starts to go down, and it looked like he (might) hit us," Mazur said. "We started to panic, because we had a lot of propane close to us for the hot tar, and he come closer and closer to us and lower."
The chopper pulled back, spun away from the school and shot straight down, Mazur said, landing hard on a strip of dirt beside a weed-covered embankment.
Mazur and his fellow workers raced down the ladder and started dialing 911.
"I see people inside," he recalled, "And see the start of spilled fuel. I was a little scared, but we made the decision; we pulled out the bodies."
The man was screaming "Help! Help!" Mazur said. They removed him out and dragged him away from the copter. The woman, whose body had shattered the front windshield on impact, was not responding, blood pouring from her mouth and nose, according to Mazur. They removed a camera from around her neck and moved her to the side as emergency responders started arriving on the scene.
The helicopter was largely intact, with one side of the bubble-like front windshield shattered, the long tail section snapped in two at the end, and camera equipment, including several smashed and mangled lenses, strewn around it.
The Robinson R22 Beta is owned by Nassau Helicopters at Princeton Airport.
FAA spokesman Jim Peters said the accident is under investigation.
