Guadalcanal, Solomon Islands, edited by M.Minderhoud
The Navy League’s Magazine “Seapower” reports on a ceremony to commemorate the 80th anniversary of the start of the Guadalcanal campaign, held in Honiara, Solomon Islands. Quite properly Vice Admiral Andrew Tiongson, Commander, U.S. Coast Guard Pacific Area, was there representing the Coast Guard.
USS Hunter Liggett (APA-14) c. 1943-44
The Coast Guard manned transport USS Hunter Liggett was flagship of Task Force 62.1 which transported the 1st Marine Division, with Maj. Gen. Alexander A. Vandegrift, USMC, Commander ground forces, embarked. The story of Douglas Munro is well know, but there were other Coast Guard heros there as well. Ultimately the Coast Guard would suffer its largest single loss of personnel in the waters of Guadalcanal, when the Coast Guard manned ammunition ship USS Serpens (AK-97) exploded on January 29, 1945, while anchored off Laguna Beach.
Some stories:
The Long Blue Line: Tulagi’s Coxswains–the services 1st Silver Star recipients
The Long Blue Line: The “Green Hell” of Guadalcanal 80 years ago!
Gold Dust Twins: The Two Coast Guardsmen Who Saved Chesty Puller’s Marines on Guadalcanal
“The Marines were being driven back to the beach and many did not have radios to request assistance. A single “HELP” spelled out in T-shirts on the ridge near the beach sent a loud and clear signal to those looking on.”
“This man is the only US Coast Guard recipient of the Medal of Honor”
Joseph Toahty, Pawnee Warrior Of Guadalcanal
Loss of USS Serpens (AK-97), Jan. 29, 1945
Chuck Hill's CG Blog 
I now the means of the explosion, but not what caused the explosion! The means being 3,399 bombs filled with Torpex! But was the initial explosion caused by a shipboard fire, sympathetic detonation, bombed, torpedoed or kamikaze…
The court of inquiry deemed it was caused by an “accident intrinsic to the loading process.”
i.e. the depth charges being loaded at the time of the explosion
More here: https://chuckhillscgblog.net/2019/09/05/what-really-happened-to-the-serpens/
Patrol Yacht USS YP-514 was also caught up in the blast, moored ~650-yards away. Soldiers ashore reported Shrapnel Rain more than a mile inland and Oil Drazzle approximately 10-miles from the blast some two hours later.
Two survived the blast on “Serpens” sleeping near the bow of the ship. Those killed outright wer 193 Coast Guardsman, 56 US Army Stevedores and 1 civilian doctor who was also onboard when the blast occurred. Remains of those killed were placed inside 52 Flag-Draped Coffins, and laid to rest in 28 graves ashore on Guadalcanal…