Mark Sean O'Donnell, 69, of Encinitas, CA passed away peacefully surrounded by his family on Wednesday, February 25, 2026. He leaves his wife of 43 years, Patricia A. (Palmer) O'Donnell, his son, Patrick B. O'Donnell and his wife Kristy, of Encinitas, CA and his daughter Megan P. (O'Donnell) Faulstich and her husband Brian of Carlsbad, CA. His three sisters, Deborah,...