US medevac plane crashes en route to help - 4 people confirmed dead

On Tuesday, four people were killed on Navajo Nation land in Arizona (US) due to the crash of a medical transport plane, according to CNN.
“The small aircraft was enroute to pick up a patient from a nearby hospital, when the crash occurred,” the Navajo Police Department said on social media.
According to their report, the crash happened around 12:40 p.m. near Chinle, Arizona.
“We extend our deepest condolences to their family and loved ones during this time,” the police added.
Meanwhile, the National Transportation Safety Board (NTSB) clarified that, according to their data, the aircraft involved was a Beechcraft 300.
“NTSB investigators are en route to the scene (and) expected to start arriving tonight. Once on site, the investigators will begin the process of documenting the scene and examining the aircraft. The aircraft will then be recovered to a secure facility for further evaluation,” NTSB spokesperson Sarah Taylor Sulick told CNN.
At this time, the cause of the crash remains unknown.
The Navajo Nation is a part of the US with special status - essentially, a state within a state. It has its government, police, courts, and laws (within the federal system).
The Navajo Nation spans three states: Arizona, New Mexico, and Utah.