Hundreds of thousands of students and adults have marked the first anniversary of the Parkland school shooting that left 17 people dead.

“It’s a permanent sore spot,” said Fort Lauderdale High School junior Jake Lynch.

“Forever, me going forward, I’ll feel this day, and this time and those names.

“It reminds me of where I want the world to be. ...

“From suffering, better things come out.”

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People of 2018: Marjory Stoneman Douglas High School students

The massacre at Marjory Stoneman Douglas High School on 14 February 2018 inflamed the national debate in America over guns, turned young people into political activists, and gave rise to some of the biggest youth demonstrations since the Vietnam era.

The moment of silence at more than 1,000 Florida schools was held at 10.17am, though the shooting actually began around 2.20pm.

School officials picked a different time because Stoneman Douglas students were being dismissed early to avoid being on campus at the hour of the attack.

The time 10.17 was selected to denote the 17 killed.

Many Stoneman Douglas students arrived wearing the burgundy #MSDStrong T-shirts that have become an emblem of the tragedy.

Outside, clear plastic figurines of angels were erected for each of the 14 students and three staff members killed.

Reporters were not allowed inside the school, but students worked on service projects as a way of trying to turn the tragedy into something positive, and grief counsellors and therapy dogs were made available along with massages and pedicures.

An interfaith service was scheduled for later in the day at a park nearby.

Freshmen Jayden Jaus and Matthew Sabia, both 14, helped mark the day by packing lunches for children in Haiti, putting rice, vitamins and soy into bags.

Many other Stoneman Douglas students skipped school. For some it was too emotional; others did not want to be in the spotlight.

Julia Brighton would not go inside, instead placing flowers at the outdoor memorial.

She said she suffered with nightmares for months.

Staying outside “felt like it would be a better experience for me instead of being at school and putting myself through that,” she said.

Alexis Grogan, a junior, said she was spending the day picking up beach rubbish, dedicating her work to those who died.

“I survived something, and I don’t want to waste what I call a second chance at life because those who have passed don’t get that,” she said.

“We have to make a difference for them.”

Classes were almost over last Valentine’s Day when authorities say 19-year-old former student Nikolas Cruz stormed the place with an AR-15 assault rifle.

Cruz, now 20, had a long history of emotional problems and threats.

He is awaiting trial.

It later emerged that fewer than 10 per cent of Marjory Stoneman Douglas High students showed up for school on the anniversary.

The Broward County school district said 291 of the school’s approximately 3,200 students attended.