A news helicopter operated for NBC4 Los Angeles crashed in the city's Chatsworth area on September 15, killing both people aboard and one person on the ground.

The aircraft was a Eurocopter AS350 B2 Ecureuil registered N358TV, according to the Aviation Safety Network. The 2004-built helicopter, serial number 3788, was owned by Tiny Bubbles Aviation and operated for KNBC as NewsChopper 4.

The helicopter had departed Whiteman Airport on a local news-gathering flight and was filming the scene of a serious collision involving an SUV and a Los Angeles Metro bus. The crash occurred at around 6:57 p.m. local time as the aircraft maneuvered at low altitude over Chatsworth.

Final images recorded from helicopter

The final live video feed from NewsChopper 4 captured the last moments before the crash. The images show the camera gradually losing altitude while warning tones can be heard in the background. The picture then abruptly turns white.

The meaning of the audible alerts is not yet known, and authorities have not determined what caused the helicopter to descend.

The aircraft struck a commercial property and was destroyed by a severe post-crash fire. Four vehicles were heavily damaged and two shipping containers were also affected. A second person on the ground was injured.

NBC identified the two people aboard as pilot George Marciniw and aerial photojournalist Eliana Moreno. Both were killed. The third fatality was a person on the ground.

Pilot George Marciniw and aerial photojournalist Eliana Moreno
Pilot George Marciniw and aerial photojournalist Eliana Moreno | Social media

NTSB investigates cause

The National Transportation Safety Board is leading the investigation into the accident, with the Federal Aviation Administration also involved.

The Aviation Safety Network currently classifies the occurrence as an accident during the maneuvering phase of an aerial patrol flight, but notes that its initial information is based on news reports, social media and other unofficial sources.

N358TV was an AS350 B2, a member of the light single-engine helicopter family originally developed by France's Aerospatiale and later produced under Eurocopter. The type is widely used for utility, law-enforcement, emergency and aerial filming missions.

Investigators will now seek to determine why the helicopter lost altitude, including the significance, if any, of the warning tones captured by its own live video feed before impact.