The FBI is searching for the owner of an unauthorised drone that crashed into a firefighting aircraft in Los Angeles last week.
One of the Super Scooper fleet's aircraft sustained wing damage and was grounded on Thursday after colliding with a civilian drone.
It is a water-bombing plane, officially named CL-415 but nicknamed "Super Scooper" due to its visually impressive water-bombing capabilities and precision in dumping sea water on specific fires.
There were no injuries, and the aircraft is expected to be operational again this week.
An FBI spokesperson Laura Eimiller said the drone had violated temporary flight restrictions imposed by the Federal Aviation Administration.
"While we have conducted a significant investigation working with our partners, we are seeking the public's help in order to identify the operator of the drone," Ms Eimiller told CBS News.
Authorities say drone users will face consequences
So far, there have been about 40 incidents where an unauthorised drone has stopped firefighters from continuing their air operations, according to California officials.
At least 24 people have died since the wildfires started last Monday, while about 150,000 people in Los Angeles County remained under evacuation orders.
Officials from across state, federal and local levels have highlighted the dangers of flying a drone near wildfires.
Los Angeles County Fire Chief Anthony Marrone said he was working with federal partners to more easily identify unauthorised drone operators in fire areas.
"The most important thing to know is that if you fly a drone at one of these brush fires, all aerial operations will be shut down, and we certainly don't want to have that happen," he said.
The FAA, which is also investigating the incident, said flying a drone near a wildfire was dangerous, and could cost lives and delay firefighting efforts.
"It's a federal crime, punishable by up to 12 months in prison, to interfere with firefighting efforts on public lands," the administration said in a statement.
"The FAA treats these violations seriously and immediately considers swift enforcement action for these offences.
"The FAA has not authorised anyone unaffiliated with the Los Angeles firefighting operations to fly drones in the [temporary flight restrictions]."
The Los Angeles County District Attorney Nathan Hochman echoed the FAA's stance on drone users operating in the temporary flight restrictions.
"You will be arrested, you will be prosecuted, and you will be punished to the full extent of the law," the district attorney said.
What are the rules around drones during Australia's bushfires?
Ahead of bushfire season, Australia's aviation regulator warned pilots and drone flyers to keep at least 5 nautical miles from any fire boundaries.
The Civil Aviation Safety Authority's CEO Pip Spence said avoiding bushfire areas meant the skies were clearer for firefighting aircraft to do their work.
"Just remember — if you fly, they can't — so think twice this fire season so that firefighting aircraft can do their part to keep local communities safe from bushfires," Ms Spence said in a statement.
"This also includes keeping your drone on the ground. Drones are small and hard to see, and pose a risk to aircraft and helicopters.
"In an emergency, you should follow the advice of your local fire authority."