The wife of a Thai Navy Seal killed while attempting to rescue 12 boys and their coach from a cave broke down in tears today (Sat) as his body arrived back to a military base in Chonburi, Thailand.

Petty Officer 1st class Saman Gunan, 38, lost consciousness during a dive while returning rescuers' used air tanks to chamber 3 inside the cave in Mae Sai district, Chiang Rai, around 1am on Friday. He did not recover.

His wife, Walepon, 35, was accompanied by her sister and other relatives on the runway as his body was carried off the plane in a wooden coffin.

Saman worked for Airports of Thailand Plc as a security officer at Suvarnabhumi airport and took time off work to help his Seal colleagues with the rescue mission on Thursday.

The body arrived back in a coffin at the naval base in Sattahip, Chonburi today at 11am local time where a funeral and religious rites were held.

Saman's wife was seen breaking down in tears as the coffin carried by military officers was carried from the plane.

His death marks the first fatality in the massive operation to rescue the group and underscores just how dangerous the voyage is going in and out of the cave, even for those who have experience.