YOKOTA AIR BASE, Japan — A U.S. sailor died early Sunday after falling from a sixth-floor balcony in Yokosuka City, according to Japanese police.

Petty Officer Second Class Alex W. Spadea, 24, a cryptologic technician, was found on the ground near his off-base apartment at 2.53 a.m., according to Japanese police.

“A Japanese citizen called Japanese Police Services (JPS) to investigate suspicious activity outside of a residence,” Yokosuka Naval Base spokesman Sean Dath said in an email. “Upon arrival, the JPS discovered the body of a young, adult male on the ground, with injuries resulting from a fall. The individual was transported to a local hospital where he was pronounced dead.”

A Japanese police spokesman said one of Spadea’s neighbors called police to report seeing him standing on their balcony earlier in the evening.

When police arrived, Spadea allegedly broke a window and disappeared. At the same time, a third-floor resident called the police to report seeing a person fall, the spokesman said.

Police believe Spadea, accidentally fell or jumped from the balcony, the spokesman said.

Empty beer cans and whiskey bottles were in the young sailor’s apartment, but it is yet to be determined if he had been drinking, the spokesman said.

Spadea, of Port Orange, Fla., was assigned to Navy Information Operations Command at Fleet Activities Yokosuka, Dath said.

U.S authorities are cooperating with Japanese police to investigate the death, and the Naval Criminal Investigative Service is conducting a concurrent investigation, he said.

robson.seth@stripes.comkusumoto.hana@stripes.com