Is this a good or a bad ending?

I personally felt that the ending was not a good one. The diary ended abruptly on the 1st August 1944 and it was later mentioned in the afterword that the Nazis broke into the Secret Annex, after being tipped off that it was Anne's family's hiding place. They then arrested all the eight people hiding in the Annex. It was also stated in the afterword that Anne died in a German concentration camp, like million other Jews. Otto Frank was the only one of the eight who survived the concentration camp, who later devoted himself to sharing the message of his daughter's diary with people all over the world. Thus, I feel that the ending to the book Diary of Anne Frank was not a good one as it is very saddening and abrupt.