The crash occurred under foggy and cloudy conditions with extremely low visibility, CNN meteorologist Michael Guy said.
Weather conditions on Sunday morning didn’t meet the minimum standards for flying and the Los Angeles Policedepartment grounded its helicopters, spokesman Josh Rubenstein told CNN.
Pictures taken shortly after the crash showed fog in the area.
Los Angeles County Fire Department Capt. Tony Imbrenda said he didn’t immediately have information about whether the Sikorsky S-76B helicopter radioed a distress signal.
“Individuals that saw the aircraft said it was coming down at a fairly significant rate of speed and impacted the ground on the hillside,” he told reporters.
Sikorsky, the helicopter manufacturer, expressed condolences in a tweet Sunday.
“We extend our sincerest condolences to all those affected by today’s Sikorsky S-76B accident in Calabasas, California,” the tweet read. “We have been in contact with the NTSB and stand ready to provide assistance and support to the investigative authorities and our customer.
Safety is our top priority; if there are any actionable findings from the investigation, we will inform our S-76 customers.”The aircraft was built in 1991, according to the FAA and registered to Island Express Holding Corp.
Calls to Island Express were not answered Sunday.