Three people were transported to hospital in critical condition after a medical helicopter crashed on a California highway Monday evening, according to fire officials.

The three injured, two women and a man, were on board the helicopter before it went down around 7 p.m. on eastbound Highway 50 near 59th Street in Sacramento, according to the Sacramento Fire Department.

One of the victims was rescued after being trapped underneath the helicopter, Sacramento Fire Capt. Justin Sylvia told reporters from the scene.

“The captain immediately sequestered the help of just civilians that were standing around. They were able to lift part of that helicopter out and get that victim out,” Sylvia said.

FAA records show the helicopter was registered to REACH Air Medical Services. There was no patient on board, but a pilot, nurse and paramedic were on board, Sylvia told reporters, adding that no cars were involved in the crash.

In a statement on social media, REACH said it was aware of the accident involving its helicopter.

“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, it said. “We appreciate the concern and support from our community and will share updates when appropriate.”

Davyd Bychkoviak told CNN he was caught in heavy traffic on the highway when he spotted the helicopter approaching and decided to start filming a video. But he soon realized the aircraft was too low.

“My first thought was that it was going to fly into me,” Bychkoviak said. “But there was a bad traffic jam so I couldn’t move – I couldn’t do anything. I thought it was going to explode, so I wanted to get away from it.”

Bychkoviak’s video shows the helicopter on its side immediately after it hit the ground, with the rotor blades still moving and smoke billowing up.

Aerial video of the aftermath also showed a red helicopter on its side with a smashed cockpit window and debris scattered over the highway surface.

“There’s a pretty large debris field,” Sylvia said, calling it “extremely lucky” that there weren’t more victims.

Fire officials and an ambulance were dispatched to the site around 7:08 p.m. local time, the department said.

The crash affected traffic with eastbound lanes completely blocked temporarily, Officer Michael Harper, a California Highway Patrol spokesman, told reporters, warning the road would be shut “for an extended period of time.”

CNN has reached out to the Sacramento County Sheriff’s Office, Sacramento Police, the Federal Aviation Administration, California Highway Patrol and REACH Air Medical Services for additional information.

According to flight tracking site Flightradar24, the helicopter had taken off from University of California Davis Medical Center in Sacramento and was heading north moments before the crash.

Weather in the area was clear and calm at the time of the crash, according to CNN Weather. (CNN)