Story highlights The youth's father was a soldier in Washington state

The teen and his family were flying to Atlanta for Christmas, fire department says

The plane made an emergency landing in Spokane

The flight had left Seattle en route to Atlanta

A 16-year-old suffered a medical emergency on a Delta Air Lines cross-country flight, and died after the flight made an emergency landing in Spokane, Washington, authorities said Saturday.

Jim Uttke, deputy medical investigator for the Spokane Medical Examiner, said it appeared the youth died of natural causes. An autopsy will be performed Monday. His name was not released.

The youth was the son of a soldier from the 16th Combat Aviation Brigade of the 7th Infantry Division out of Joint Base Lewis-McChord at Fort Lewis, Washington, a U.S. military official said. The youth was traveling with mother to join his father who'd gone ahead to a new base, the official said.

The Spokane Fire Department said on its Facebook page that the youth was part of a military family flying to Atlanta for Christmas.

Delta Flight 128 was bound for Atlanta from Seattle on Saturday and was diverted to Spokane after a medical emergency, Delta spokesman Michael Thomas said.

Thomas said the plane carrying 258 passengers was scheduled to land in Atlanta at 4 p.m. ET Saturday. It's now expected to arrive about 11 p.m.