Three people are in a critical condition after a medical helicopter crashed on a freeway in Sacramento, California on Monday evening.
Flight Radar data shows flight REH5 leaving UC Medical Centre at 7:05pm (local time), and the track ends before El Dorado Freeway, also known as Highway 50.
The aircraft had previously arrived at the medical centre from California's Redding Regional Airport, about 150 kilometres north of Sacramento.
Vision shared on social media appeared to show a helicopter rapidly losing altitude before crashing behind a concrete median barrier on the freeway alongside a grassy hill.
Sacramento Fire Captain Justin Sylvia said a pilot, nurse and paramedic — one man and two women — were on board the helicopter and had been transported to local hospitals.
He said one woman was pinned under the helicopter when it crashed and was rescued by nearby civilians who were able to lift the helicopter before emergency services arrived.
"People reported that they basically saw the helicopter kind of going down quickly. So all the traffic slowed down," Mr Sylvia said.
"It took every ounce of all approximately 15 people to move that aircraft up just enough to get her out."
Sacramento Mayor Kevin McCarty confirmed on X the crash occurred on eastbound Highway 50, west of 59th Street.
"Thank you to our brave first responders & ~15 bystanders who assisted Sac Fire until more units arrived on scene," he wrote.
"Survivors are being treated at local hospitals."
The highway was initially shut down after the crash, but cement blocks have since been moved to allow traffic through.
Eastbound lanes remained closed for several hours, before a single lane began to reopen at 10:30pm local time.
California's Highway Patrol was the first emergency responder and has tasked Multidisciplinary Accident Investigation Team (MAIT) specialist investigators with examining the crash site.
It is expected that Californian authorities will hand over the investigation to the Federal Aviation Administration.
Captain Sylvia said the helicopter had landed upside down on the freeway, and it was "lucky" it had not burst into flames.
He said that a potential fire sparked by jet engine fuel would have significantly hampered any emergency response to the crash.
The aircraft wreckage appeared to have sustained significant damage to its fuselage in the crash, including a large crack between its airframe and tail, and large chunks of grass stuck in the underside of the helicopter's tail rotor.
Sacramento City Councillor Lisa Kaplan said she was on a ride-along with police responding to the crash and said there were plumes of white smoke coming out of the crashed helicopter.
"It's really sombering and sobering. I am up flying with sheriff pilots that do this day in and day out. And it really makes you grateful for every day and grateful for our officers and our medical pilots," she said.
Flight Radar data shows the aircraft was an Airbus H130 single-engine helicopter, operated by the Sacramento-based REACH Air Medical Services organisation.
The REACH website said the organisation "provides critical care air and ground transport service to communities throughout California, Nevada, Oregon, Colorado and Wyoming", involving hundreds of trained nurses, paramedics, pilots and aircraft technicians.
"We are aware of an accident involving a REACH Air Medical helicopter on Highway 50 in Sacramento this evening and are keeping all those impacted in our thoughts and prayers," a statement from the company said.
"We are in the process of determining the details of this situation, as well as the condition of the REACH crew involved, who were all taken to area hospitals. We will continue to provide information as it becomes available.
"There was no patient on board."
Mr Sylvia confirmed all three passengers were in a critical condition, but the extent of their injuries was unknown.
He said no other vehicles were impacted by the crash.
ABC/Wires
