https://www.azcentral.com/story/news/local/phoenix-breaking/2016/08/08/phoenix-fire-crews-working-confined-space-rescue-daisy-mountain/88435634/

https://www.12news.com/video/news/local/valley/equine-vet-william-tryon-dies-in-tragic-accident/75-2326205

https://www.abc15.com/news/region-phoenix-metro/north-phoenix/vigil-held-for-veterinarian-dr-bill-tryon-killed-after-falling-into-underground-grain-storage

https://www.legacy.com/obituaries/name/william-tryon-obituary?pid=181050706