February 7, 1973July 7, 2020

SEAN A. CASSIDY February 7, 1973 – July 7, 2020

On Tuesday, July 7, 2020, Sean A. Cassidy, age 47, beloved son of Michael J. Cassidy and Beverly A. Terlep; loving brother of Erin Cassidy (Paul Niskanen) and Christopher Cassidy (Can); and uncle of Adam, Noah and Bianca Niskanen and Charles Cassidy, died at home from an apparent heart attack and complications of diabetes.

Born and raised in Oakland, California, Sean attended Corpus Christi Elementary School in Piedmont, St. Mary’s High School in Berkeley, Laney College in Oakland, and received his Bachelor of Science degree from U.C. Berkeley, with a major in Biology and the intention of becoming a paleontologist.

From childhood on, Sean was an adventurer. He played hot basketball in grade school, loved to ride his bike and later his motorcycle, was highly skilled in doing tricks on his skateboard, and loved playing video games. He discovered his love of music during his teen years, teaching himself how to play keyboard, drums, and guitar, playing both classical music and soft rock. He also composed his own music.

Unfortunately, just as he was finishing college, he began to show signs of schizophrenia. Through the following years, Sean struggled with his illness, but he loved his family and tried to stay connected with them as long as he could. Over the years, even in the midst of his illness, he pursued his artistic endeavors, making special Christmas ornaments and treats for his family, carving and painting didgeridoos, making a beautiful wooden mirror frame for his mother, designing patterns to decorate his clothing, sewing martial arts clothing, and designing and constructing a big skateboard ramp.

Sean had such a gentle and sensitive spirit that the neighborhood birds and squirrels would eat peanuts out of his hand. As a child, his favorite of the family’s three cats was Shadow, a sleek black cat, and Sean always managed to find Shadow in time to take her with him to bed. When our neighbors’ dog, Blitz, who was part wolf, was dying of cancer, Sean took care of him while they were on vacation and sat with him on the front porch.

After many years of suffering with several physical illnesses which went largely untreated because of his mental illness, Sean went home to God and is now at peace.

Sean is also survived by his aunt Pam (Gary) Harbaugh; cousins Jessie Pemble, Scott (Stacey) Norton and son Jake (Anna), Michele Norton, Jennifer Norton and daughter Caitlyn, Jeff (Brenda) Norton and children Tyler, Reese, and Cade, Amy (David) Adornato and children Kate and Grace, Sister Albert Marie Papesh, Diane (Terry) Malone and son Sean, and cousin/godparents Amy and Etsie Foreman and children John, David, and Daniel; as well as other relatives.

Many friends have known and loved him for most or all of his life. These include Barbara Gunderson and her daughter Genevieve (Phil) Rados and their children; Sharon Dobie and son Nick; Larry (Beth) Carducci and children Matt and Julie, and their children; Ann Mora and daughter Kate; Pat Morris and children Kevin and Emma (Ed Kress) and children; Sandy and Dave Ramet; Jacquie Smith and daughter Tierney and other friends.

A celebration of Sean's life will take place at St. Mary Magdalen Catholic Church on Monday, July 27, 2020, at 10:00 am Pacific Time. Because of the Covid-19 virus, only a very small number of people will be allowed to attend, but the Mass will be live-streamed. If you wish to celebrate with us, please email the family at to receive a link to attend virtually.

In lieu of flowers, donations to the National Alliance on Mental Illness (NAMI), Brain and Behavior Research Foundation, or the Diabetes Research Institute would be appreciated.



have a memory or condolence to add?

David Koreski (Uncle Dave) Pleasant Hill

July 23, 2020

Dear Bev, Mike, Erin, and Chris,

I only knew Sean when he was a child visiting with you all at my sister Jan's house, but I have many memories of him with Erin (and Chris when he was older), Matt, and Julie chasing each other outside or through the house, and laughing with joyful abandon. I remember Sean mostly as joyful, with a big smile on his face. I am glad those are my memories of him, and I want you to know those memories as well, so you might be comforted knowing that he knew such joy. Know that I am thinking of all of you, and sending much love. I am also thinking that Jan just might be showing him a different kind of home now... and together they are laughing and running about it with joyful abandon.

Love to you all.

Gladys Ingle Oakland

July 23, 2020

Dear Bev, Mike, Erin and Chris, I'm so sorry to hear about Sean, and please know that you are all in my prayers. May God be with you and your families during this time.

Jabari Atlanta

July 17, 2020

Bev, Mike, Erin and Chris - I will keep you in my prayers. You know that Sean and I had many good times together. Together, we will cherish the memories. He's an extraordinary man and will be missed. May God continue to comfort and keep you.

Pam and Gary Harbaugh Oklahoma City

July 14, 2020

Bev, Mike, Erin, and Chris- You are all in our hearts and prayers with the passing of Sean. He was an amazing person and so very talented. A memory I have is being at your house and we (Bev, Mike, Erin, Sean, and I) were playing Trivial Pursuit. I fondly remember him "kicking our butts" and winning all the pieces of pie! I was amazed how smart he was for a small child and in awe. Or the time we were at Stintson Beach and I was watching the teen-aged boys (Scott, Sean, and Chris) playing Hacky Sac! I will always hold those memories dear in my heart. Sending you all hugs.

Michele Norton Madison

July 14, 2020

Dear Uncle Mike, Aunt Bev, Erin, and Chris: I'm so sorry for your loss. Sean was a wonderful, beautiful person. May your family keep the wonderful memories of all of the loving times together.

July 14, 2020

July 14, 2020

Erin, Sean and Chris