A journalist and pilot have been killed in a news helicopter crash. The National Broadcasting Company news helicopter crashed in the Chatsworth area of Los Angeles on Tuesday evening, leaving three people dead and one injured.

The network, which confirmed the development during a live broadcast, said the news chopper 4 crashed while covering a deadly bus collision involving a Los Angeles Metro bus and a passenger vehicle.

Its reporter Eliana Moreno and pilot George Marciniw were among those killed in the crash.

Footage of the incident showed an alarm sounding as the engine noise changed and the image started spinning rapidly before the broadcast was disconnected.

The crash, which was reported shortly before 7:00 p.m. local time in Chatsworth, saw the helicopter come down near commercial buildings and catch fire, with flames affecting vehicles and containers.

“We’ve been telling you that we’ve been piecing it together here. We knew it was a news chopper. We knew we’d lost contact with our people out there, and we’ve just received the confirmation that, in fact, NewsChopper 4 went down just before 7 o’clock tonight in Chatsworth,” anchor Colleen Williams said on air.

NBC, however, did not publicly disclose how many people were aboard the helicopter.

Los Angeles Fire Department said three people were pronounced dead at the scene while the fourth person was taken to a local hospital.

Its spokesman, Branden Silverman, explained that the helicopter was almost destroyed, adding that investigators would have to search the wreckage to determine how many people were aboard.

The National Transportation Safety Board and the Federal Aviation Administration said they would thoroughly investigate the crash.

Los Angeles Mayor Karen Bass described the incidents as tragic and condoled with the victims’ families.

“This is a tragic night for Los Angeles. My thoughts are with those impacted by the bus collision and the helicopter crash, and with the entire NBC4 family who lost members of their team while they were doing their jobs.

“I’m deeply grateful to our firefighters, paramedics, and police officers who responded immediately to two incredibly difficult scenes to save lives and render aid,” Ms Bass stated.