He then gained a full-time position with Emsco Refractories, located at 8661 Dorothy Ave. in South Gate, whose specialty was aircraft manufacture "but had a subsidiary business producing very high temperature-resistant ceramic tiles" as well as bricks. Keeler died of inadvertent cyanide inhalation while working in his Emsco Refractories laboratory. He had forgotten to turn on the exhaust fan in the lab and, incidentally, someone had carelessly left a beaker of uncorked cyanide on a nearby workbench, its odorless vapors already extant in the room. Keeler died ten days later, on Oct. 29, 1934. His wife, Mary, continued to live in the home Keeler had built for the family in South Gate, remaining in residence there until 1983, when her son, Philip, had to move her to a nursing home in Orange County, California. Through a series of fortunate events, a man named Brian Kaiser was able to purchase the home and has since become an expert on Rufus Keeler, his tile-making, and Southern California tile companies of the early 20th century, lecturing on the topic and acting as a consultant for tile preservation projects. Meanwhile, Keeler's products remain extant throughout Southern California and beyond, public examples of which are the aforementioned Roosevelt Hotel, Los Angeles City Hall, Geffen Playhouse, Mayan Theater, Dana Junior High School in San Pedro, and Adamson House in Malibu as well as the Watts Towers in Watts, California and Serra Retreat in Malibu.