One of the largest losses in stop motion history is probably Aardman Animations' warehouse fire in October 2005. In much the same way Laika has stored its history in the attic in Portland Oregon, Aardman had a warehouse full of their entire history in Bristol.
According to a CNN.com article at the time, "the warehouse contained sets, props and models from the company's productions, from the children's cartoon character "Morph" through the Oscar-winning, anthropomorphic "Creature Comforts" series to the Wallace and Gromit films."
A Close Shave, A Grand Day Out and the Wrong Trousers are three of possibly the studios most popular films, and they suffered the most loss. The original negatives from the film luckily were stored somewhere else and still survive.
The fire made its way through the three floors during the night in the warehouse and eventually the fire got so hot, all the floors collapsed onto one another. The fire was ruled as electrically started and not arson. Mostly stone and silicone molds were salvaged from the fire and Aardman had said they would be re-making many of the most memorable losses. Including Chicken Run puppets.
According to scotsman.com "the well-known rocket from A Grand Day Out was spared, as it had been on display at the company's studio, while models and props from Aardman's latest feature, Wallace & Gromit: The Curse Of The Were-Rabbit, were kept at the company's Bristol studios and were unaffected."
The fire department at first thought it may have been arson, but later it was found that it was not set intentionally by anyone. It wasn't the first fire Aardman had been through. In fact during December 2001 the studio had a small building catch fire with their engineering equipment and other flammable items go ablaze. There were no puppets or props inside it.
Visit Aardmans web site at http://www.aardman.com/
Stegosaurus from the original KING KONG (1933) (articulated armature used to animate the model is visible in the deteriorated tail) the ORIGINAL BRONTOSAURUS from KING KONG (1933) -- the one who ate all the sailors
Bob Burns Kong and Mighty Joe Young Puppet armatures
Peter Jackson stop motion puppets from the original King Kong
George Lucas archive: Stop motion puppets from Willow, the At At walkers and more
Ray Harryhausens and his own creations which are in his home in the UK