A 4-month-old infant from Canada is dead after a flight to Honolulu.

Honolulu police spokeswoman Michelle Yu said the boy was rushed to a hospital Sunday after he became unresponsive during the flight.

The baby was pronounced dead just before midnight. There are no signs of foul play.

The Medical Examiner’s Office conducted an autopsy on Monday, but doctors say they need more information to determine the cause of death.

The Medical Examiner’s Office said the boy was from British Columbia.