A 1-year-old Japanese boy fell unconscious on a flight from Narita, Japan, to Honolulu yesterday morning, one hour before landing, and was pronounced dead at a Honolulu hospital, authorities said.

The boy was identified as Hyeondo Seo of Tokyo.

An autopsy is scheduled for today to determine the cause of death.

The child's medical history is unknown, said Department of Transportation spokeswoman Tami Mori.

The child was on China Airlines Flight 18 with his parents when he went into cardiac arrest an hour before arrival, Mori said.

A doctor on board performed cardiopulmonary resuscitation, she said.

The plane arrived in Honolulu at 7:03 a.m. Ambulance, sheriffs and a medical team were standing by.

The baby was taken to Kaiser Medical Center in Moanalua, where he was pronounced dead at 8:01 a.m. yesterday.

Police said there were no signs of foul play.