Delaney Tarr says Valentine's Day was supposed to be a time to celebrate beauty and love but instead turned into a day of fear when a gunman attacked her Florida school.

But now she's finding inspiration among others who overcame heartbreak half a world away.

The 18-year-old senior is one of 28 students from Marjory Stoneman Douglas High School in Parkland, Florida, who are visiting New Zealand this week.

The goal of the trip is for the students to learn how to keep a youth movement going long after a tragedy has faded from the headlines.

The model is New Zealand's Student Volunteer Army, which began helping citizens in Christchurch after earthquakes devastated the city, including a 2011 quake that killed 185 people.

More than seven years later, the group is continuing its civic-minded work.

As part of their visit, the Florida students planted 17 trees to commemorate each of the students and staff members who were killed at their school. They placed pictures and notes with the saplings, and recounted memories of their former classmates and mentors in a ceremony that brought many of them to tears.

While the tragedies in Florida and Christchurch came from very different origins, both groups of students say they feel a common bond.

Tarr said the students in both countries banded together and got something done.

"We will never be able to really experience Valentine's Day, to experience school, to experience life in the same way that we used to," she said.

"And while that is heartbreaking, we've tried to make the most out of it. We've tried so hard to make some positive change out of something that never should have affected us, never should have affected anyone. And ultimately, that's why we are here now. Not as much to mourn the past but as to look forward to the future.

Tarr and many of the other Parkland students have become known around the world for their passionate advocacy of gun control.

Tarr said they have faced their share of backlash, and they try to stress they're not against the Second Amendment, but instead believe there are reasonable limitations to be placed upon it.

The debate can seem foreign to many people in New Zealand, where gun violence is rare. 
And perhaps because of that, gun control hasn't been a major focus of discussion during the trip.

Rather, the discussions have been about leadership, developing social influence, and affecting grass-roots change.

And for many of the Florida students, it's about experiencing a place they might have only heard about in a geography class or seen in a movie.

The students are paying for a portion of their trip while other contributions have come from fundraising and grants.

"It was said to us yesterday ... that you could either fall apart, when tragedy happens, or you can band together and become stronger," said Danielle Driscoll, a teacher at Marjory Stoneman Douglas High School who is accompanying the students.

She said both the New Zealand and Parkland students had gotten stronger.

Former student Nikolas Cruz faces 17 counts of first-degree murder and 17 counts of attempted murder in the shooting.

-AP