Media Factory have made an official announcement that Noboru Yamaguchi, the author of the Zero no Tsukaima light novels, passed away from cancer on 4th of April. A funeral was held on the 10th by family and relatives, and the announcement was made on the 11th.
Yamaguchi had been continuing to write the Zero no Tsukaima novels and reached a total of 20 novels before he passed away. Unfortunately, he was unable to finish the series. He had other multiple light novel works he was known for, such as Strike Witches and Green Green, but Zero no Tsukaima was his most well known work.
Source: Media Factory