William Sadilek was born on May 9, 1961, in San Francisco, California. He was commissioned an Ensign in the U.S. Navy on December 18, 1983, and immediately attended Basic Underwater Demolition/SEAL training at Naval Amphibious Base Coronado, California, from January to July 1984. After completing Swimmer Delivery Vehicle Operator training, LtJg Sadilek served with SEAL Delivery Vehicle Team ONE (SDVT-1) until he was killed in a training accident near Naval Submarine Base Bangor, Washington, on February 19, 1986.

The Sailor's Creed:

I am a United States Sailor.

I will support and defend the Constitution of the United States of America and I will obey the orders of those appointed over me.

I represent the fighting spirit of the Navy and those who have gone before me to defend freedom and democracy around the world.

I proudly serve my country's Navy combat team with Honor, Courage and Commitment.

I am committed to excellence and the fair treatment of all.