Simons and his second wife, Marilyn Hawrys Simons, co-founded the Simons Foundation in 1994, a charitable organization that supports projects related to education and health, in addition to scientific research. In memory of his son Paul, whom he had with his first wife, Barbara Simons, he established Avalon Park, a 130-acre (0.53 km) nature preserve in Stony Brook. In 1996, 34-year-old Paul was killed by a car driver while riding a bicycle near the Simons home. Another son, Nick Simons, drowned at age 24 while on a trip to Bali in Indonesia in 2003. Nick had worked in Nepal. The Simons have become large donors to Nepalese Health care through the Nick Simons Institute.