Navy investigators were still looking for answers today as to why a 22-year-old submarine sailor on a security detail opened fire on Pearl Harbor Naval Shipyard workers last week, killing two and wounding a third before turning a gun on himself — all in the span of less than 30 seconds.

Shipyard apprentice Roger Nakamine, 36, the wounded man, has been released from The Queen’s Medical Center, the hospital said today.

Machinist’s Mate Auxiliary Fireman Gabriel Antonio Romero of Texas, identified as the shooter in last Wednesday’s tragedy, reported to the attack submarine USS Columbia on June 28, 2018, according to Joint Base Pearl Harbor-Hickam.

The two dead shipyard civilian employees are Roldan A. Agustin of Hawaii, 49, a shop planner (nondestructive testing); and Vincent J. Kapoi Jr., 30, a metals inspector apprentice.

Agustin, a retired Hawaii Army National Guard staff sergeant, was deployed twice — once to Afghanistan and once to Kuwait — as an aviation maintenance specialist.

The Columbia entered dry dock 2 at Pearl Harbor in October for a two-year overhaul, officials said previously.

Romero was a student with recruit training command in Great Lakes, Il., from Dec. 11, 2017, to Feb. 3, 2018, and a student at Navy Submarine School in Groton, Conn., from Feb. 3, 2018 to June 15, 2018, according to the joint base.

Base officials are attempting to set the record straight, meanwhile, as to what did and did not happen with Romero amid a variety of reports, but information still is only slowly forthcoming.

Base spokesman Chuck Anthony said he could offer no insight as to whether Romero had been undergoing a disciplinary review and was taking anger management classes.

“I’m not able to confirm or debunk” that information, Anthony said. “It is part of the investigation.

The FBI said the attack by Romero appeared to be an isolated incident and was not motivated by any ideology.

The Associated Press reported that Romero was unhappy with his commanders and faced non-judicial punishment. Romero was armed with an M-4 rifle and 9mm pistol for duty providing security for the USS Columbia while it was in dry dock, according to reports.

Anthony said the shipyard has returned to regular business, but Emergency Family Assistance Center teams “are still there on a daily basis. Clinical psychologists and counselors have been going to the shipyard to offer their assistance.”

There have been no other suicides on the Columbia in the past few years, as was previously suggested, Anthony said.

Submariners get mental health screening while in training, he said.

“The SUBSCREEN test is a mental health screening test that is administered to enlisted personnel and officers in training to become submariners,” Anthony said in an email. “The test measures submariners on traits that may be incompatible with service in the submarine force (i.e., anxiety, depression, suicidal thoughts).”

If a potential submariner exceeds one or more of the test’s referral thresholds, that individual is referred for an interview with a mental health clinician, he said. A recommendation is then made to keep the submariner in training, make a referral for Navy service other than in the submarine force, or pursue a separation from the Navy.

Star-Advertiser Staff Writer Leila Fujimori contributed to this report.