Some of the biggest planes used by the California Air National Guard to fight fires have been grounded. The order is a response to the crash of a C-130 air tanker in South Dakota that killed at least two of the plane's six crew members.
The type of plane that crashed uses a special Modular Airborne Firefighting System or MAFFS.
California has two such planes fighting fires in Colorado.
The Wyoming Air National Guard has been supervising the specially-equipped C-130s flying in Colorado and South Dakota. They Wyoming Air Guard told the seven units nationwide that use the system to stand down at least for 24 hours.
The plane went down early Sunday evening while the crew was dropping retardant on the Whitedraw Fire in southwestern South Dakota.
Investigators have not determined a cause of the crash.