The FAA and NTSB are investigating what went wrong.
The incident occurred around 7:43 p.m. on Monday, near the intersection of Cannon Hill Road and Musket Road.
Penn Medicine said Tuesday that the helicopter was traveling from Wings Field Airport in Blue Bell to pick up a patient at Chester County Hospital when the pilot had to make the emergency landing.
It's not yet known why the pilot had to land.
Medical helicopter makes emergency landing in Montco neighborhood
Officials say there were three flight crew members onboard. One of them was taken to the hospital to get checked out, but officials say everyone is going to be OK.
Video from a nearby resident captured the aircraft descending into the neighborhood.
Video captures moment medical helicopter makes emergency landing
"I see the helicopter coming right down toward my backyard, and I started recording. I was in shock," recalled Eric Ford of Whitemarsh Twp.
"The helicopter came in this way, and the propeller on the side fell off. And so that was in one yard on the way. It was going one direction, kind of turned around and landed in a person's front yard," added another resident, Brad Ingram.
During a news conference, Whitemarsh Township Police Chief Christopher Ward spoke about the pilot's control under chaos.
Officials hold news conference on Whitemarsh medical helicopter emergency landing
"We got very lucky tonight. It's a miracle. The pilot did an amazing job from all accounts, as out of control as it was," said Ward. "He controlled it into an area and was able to put it down without striking, luckily for us, any homes, any vehicles or any people."
As fire and police officials filled the neighborhood, they blocked off certain areas, including Kieran Sheehan's backyard, where you can seethe tail rotor from the chopper.
"I hear like the plane, our entire house shook. Then we go outside, and there's a piece of it in our backyard," recalled Sheehan.
Residents are urged to call 911 if any pieces of the aircraft are spotted.
The NTSB told Action News it is investigating and more details could be released on Tuesday.