Chief Petty Officer Charles "Chuck" Humphrey Keating IV - known to friends and family as "C4" - was a US Navy Seal who was killed in action
on May 3, 2016, while attempting to rescue US Military advisers that were pinned down by ISIS fighters in the Iraqi town of Telskof.

As for the name, it can be traced back to Keating's Memorial service where friend Ian Urtnowski distributed t-shirts with Keating's initials, photo and "Chuck Heavy" on them. As Urtnowski explained it "We call it Chuck heavy, cause Charlie’s beer of choice was Budweiser. He didn’t drink Bud Light, he drank Bud Heavy and heavy just sums up the whole emotional feeling for all of us."