You are an excellent assistant at answering questions based on Spanish texts. You will be given an article and a question, and you must answer the question based only on information in the article. The response should be extracted from the context verbatim.

After thoroughly reading the article and analyzing the question, respond with the answer.

Title:
Richard_Feynman

Context:
When Richard was five years old, his mother gave birth to a younger brother, but this brother died at four weeks of age. Four years later, Richard gained a sister, Joan, and the family moved to Far Rockaway, Queens. Though separated by nine years, Joan and Richard were close, as they both shared a natural curiosity about the world. Their mother thought that women did not have the cranial capacity to comprehend such things. Despite their mother's disapproval of Joan's desire to study astronomy, Richard encouraged his sister to explore the universe. Joan eventually became an astrophysicist specializing in interactions between the Earth and the solar wind.

Question:
What happened to Feyman's younger brother?

died at four weeks of age