Schoolchildren statewide won’t be scurrying for shelter Friday when officials sound an “attack warning” siren in the first test of its kind in decades.

But they have been preparing since at least August for the unlikely event of a North Korean nuclear missile strike that still feels more 1950s Cold War than 2017 reality.

A Nov. 9 letter went out to parents of children at Kaelepulu Elementary School in Kailua saying that following guidance from the state Department of Education and Hawaii Emergency Management Agency, the school’s safety committee looked at “emergency lockdown preparedness.”

“The committee has come up with a plan for the unlikely event that would require an ELP of 24-72 hours,” including the creation of a “courage kit” for each student.

Each kit, to be prepared with assistance from parents, was recommended to include a “comfort letter” with photos of family and nonperishable food. In conjunction with those efforts, donations of cases of bottled water, flashlights, batteries, duct tape and Clorox wipes were being sought for “classroom courage kits.”

At Kaimuki Middle School, in the case of North Korean nuclear attack, kids were told to get to certain classrooms, close the windows and turn off the air conditioning. They were also told about “pee buckets” they would be using.

Hawaii Emergency Management Executive Officer Toby Clairmont previously said the last time Hawaii residents heard the attack warning siren test was around 1980 during the Cold War.

At 11:45 a.m. Friday, during the regular monthly siren test, 50 seconds of the usual steady-tone alert for hurricanes or tsunamis will be followed by 50 seconds of the wavering attack warning tone, the agency said.

The agency, formerly state Civil Defense, has said repeatedly that a North Korean attack is highly unlikely but that its responsibility is to prepare for threats. The state, including its schools, has attempted to develop planning while not generating hysteria.

The state’s latest 30-second public service announcement strives for a nonthreatening tone. Ukulele music plays as Hawaii Emergency Management Administrator Vern Miyagi states, “On the first business day of every month, the state and the counties normally conduct a test of the attention alert signal, which is a steady tone. Starting Dec. 1, a second tone, the attack warning signal, a wailing tone, will be added. The attack warning signal advises everyone to take immediate shelter — get inside, stay inside, stay tuned.”

Dann Carlson, assistant superintendent, Office of School Facilities and Support Services, sent out a memo in August titled “North Korean situation, emergency preparedness.”

In it Carlson said the proper response to the attack warning siren — other than in tests — is to shelter in place. The memo advises schools to identify safe areas in each building and to prevent outside air from mixing with inside air. The note calls for the use of plastic sheeting, wet cloth and duct tape to seal windows and cracks to minimize air contamination.

“Emergency preparedness is a high priority practiced in our schools,” Department of Education spokeswoman Donalyn Dela Cruz said in an email. “In working with HI-EMA on nuclear preparedness planning, shelter-in- place practices and procedures are in place.”

All Hawaii public schools are required to practice five types of drills at least once annually, including for earthquakes and tsunamis, as well as shelter in place, lockdown and evacuation, she said.

Schools can add aspects of their plan that are unique to their community. Dela Cruz said there are no drills scheduled for Friday, and schools can conduct the required preparedness exercises at any time.

Kaelepulu Principal Jamie Dela Cruz said in response to the DOE directive, “We just thought, well, in general, when we’re looking at addressing our own emergency preparedness, what might we need should we have to sequester in place for a while?”

The “courage kits” are an extension of the school’s “social-emotional” learning program, while any collected water can eventually be used at school functions and nonperishable food can be given to food banks, the principal said.