BREAKING: NBC LA NewsChopper4 crashes in fireball during live shot, killing 3

NBC Los Angeles confirmed that the aircraft involved was NewsChopper4, the station's helicopter, which had been operating in the Chatsworth area as news crews covered a separate deadly collision involving a Metro bus.

NBC LA said it had "lost contact" with the reporter and pilot aboard the helicopter following the crash. Their conditions were not immediately confirmed by the station.

Fire officials told local media that a person on the ground was killed when the KNBC helicopter crashed. Authorities initially reported three people dead and another person hospitalized following the fiery wreck.

Video circulating on social media appears to show the final moments from NewsChopper4's live broadcast before the aircraft went down. The helicopter's camera was trained on the crash scene below when the aircraft suddenly appeared to lose control. Audio from inside the helicopter captured a brief exchange as the situation deteriorated, with a voice appearing to ask whether the pilot could "pull up" moments before the transmission ended.

The footage then cuts away. The precise wording of the exchange has not been officially confirmed.

The helicopter went down shortly before 7 pm in the 9100 block of North Mason Avenue, according to the Los Angeles Fire Department.

The aircraft crashed between two commercial buildings and caught fire. Four vehicles and two storage containers were also damaged in the blaze. The identities of those killed had not been released.

Several television news helicopters had been operating over the western San Fernando Valley at the time, covering a separate Metro bus crash in Chatsworth that left two people dead and multiple others injured.

The helicopter was so badly damaged that firefighters initially could not identify it from its tail number. "From the helicopter itself, it's pretty well destroyed," LAFD public information officer Brandon Silverman said. "So we are going to have to go through the rubble and see how many victims there were on board, as well as identify the helicopter; we couldn't even see a tail."

A witness said the helicopter erupted in a fireball immediately after striking the ground in a parking lot.

Los Angeles Mayor Karen Bass issued a statement following the two deadly incidents. "I’m absolutely devastated by the loss of life in Chatsworth tonight," Bass said. "My heart is with the families and loved ones of those we lost in the tragic bus collision and helicopter crash."

The National Transportation Safety Board was gathering information about the helicopter crash and was expected to determine whether investigators would be sent to the scene.

The cause of the crash remained unknown.