Neill Ellis travelled from his home in the Bay of Plenty to "Tornado Alley" in the United States to fulfil a lifelong dream.
But what he witnessed when a huge twister ripped through the community of Moore on the outskirts of Oklahoma City was the stuff of nightmares.
The Tauranga man was the only Kiwi in a group of Australian and American storm-chasers on a five-week trip to the region, where tornadoes are a regular occurrence.
"These things are amazing to see - they're beautiful - but only when when they're out in the fields," Mr Ellis said.
He thought the trip, which he had planned for years, might be a disappointment because cold weather kept tornadoes at bay for the first few weeks.
But activity increased and he witnessed at least nine tornadoes, including one last week which devastated the Texas town of Granbury, killing six people.
"The last couple of weeks have been pretty spectacular," he said.
On Monday, the group stopped for lunch in Oklahoma City before chasing some weather systems developing to the south.
"We didn't get that far because we realised that the latest couple of radar scans showed a rapidly-developing supercell thunderstorm approaching Oklahoma City on a direct-hit path.
"We did a U-turn and came back into the city. It developed really rapidly and we got ourselves in a spot where we could see it [the tornado] cross I-35 - the interstate highway - pretty much right in front of us."
They were about 1km away from the huge tornado, which spat debris as it shifted towards them.
"The roar from this thing was just incredible. It was a very, very scary noise," he said.
"I can't describe what it was like, you had to be there, the video footage just doesn't do it justice."
They fled as it got closer and the debris started getting larger, but returned about an hour later to see if they could help.
"We got some gloves on the way back in, not only for us but some extras as well, and we helped with the search and handed out gloves to people who were looking for their stuff.
"It was terrible. I've never seen anything like it. And we weren't even in the worst-hit side of town."
He and his group helped look for survivors and to recover people's belongings until it was dark, and when police told them to move on.
The group also went to Plaza Towers Elementary, the school demolished in the twister, to hand out sandwiches and bottles of water to rescuers who had spent hours searching through the rubble.
"We saw parents there who were asking questions of us but we didn't know what was going on and that was just terrible. It was probably the hardest part of the whole thing actually, not being able to tell them anything. They were desperate for answers and nobody had them."
Mr Ellis said he and others on the ground were still trying to comprehend what they saw.
"To be frank, I haven't looked at any of the media coverage. It's been pretty hard on all of us and I've just chosen not too."
Mr Ellis flies back to New Zealand on Monday, where he is to resume his job as a biomedical technician.