Mr Endo didn't die, Mrs Endo died because the house they lived in was old and the roof collapsed on top of her when she was sleeping and she was trapped. She died of lack of oxygen (suffacated).
Mr Endo was at his sons house at the time, this house was newer and earthquake proof. He survived, and on the 19th of January (2 days after the earthquake) Mr and Mrs Endo's son found Mrs Endo's body with help from his friends.