Ms. Hazel became the first black school crossing-guard in Baltimore, Gaston said. She also worked 35 years as a substitute teacher for Baltimore City Schools. Later, she adventured in Paris, Italy, France. Her travel photos filled albums as thick as phone books, each picture carefully notated with the dates, names and descriptions she wrote on her typewriter: Here she is on a sun-washed Hawaiian beach; there, atop the Great Wall of China.