A centre for the developmentally disabled, that is within the Inland Regional Centre where the shooting took place in San Bernadino, had just hosted a children's Christmas party the day before the tragedy.
A video posted on Twitter shows wheelchair-bound children dancing and singing at the centre.
At least 14 people were killed and multiple injured in the mass shooting at the Inland Regional Centre today.
A photo posted on the centre's Facebook page shows a child beaming as he receives a gift from Santa.