Sorry your brother is so upset. I cried buckets when my two hamsters died. They were such great personalities and I took them everywhere on holiday. Doesn't matter how big or small an animal is or how long you have them for. You always feel a loss when they go.
Big hugs to your brother. You do get over it and look back fondly at the funny moments. I still have my dvd remote control with a little hamster toothmark in from when I had them 8 years ago.