The family offered most of Mr Lynch's household furniture including a refrigerator, beds and appliances to people who needed them and were planning to go through the rest and retain keepsakes for the family.
The offer was made through the Wairarapa free, buy and swap Facebook page.
However, between last Friday and Sunday, someone had broken in, stealing the microwave oven, tools and other items the family wanted to keep, leaving them gutted at the thieves' actions.
The thieves left behind a box of empty beer bottles outside and a couple of empty bottles inside the house.
"Dad went down on Sunday to sort out some of the things and decide what we were going to keep and someone had already taken most of it."
They have notified police but don't hold out much hope.
"We don't even know everything that has gone and our [grandfather] isn't here to tell us what is missing.
"We know the microwave and a whole bunch of tools are gone.
"Police can't do much really. People could have waited though or just asked us if they needed something, not gone ahead and helped themselves."
If you know anything about the burglary please contact Featherston Police (06) 308 9044.
