She said they were quickly ushered off their bus and into their hotel.
"[We] didn't really know what was going on. Most phone lines are blocked because so many people are calling and WiFi is slow so we are getting drip fed info."
Houghton said New Zealand media were "much more on to it than French media".
She said there were "many panicked people" in the hotel.
"We could hear what we thought were gunshots although we thought they might be fireworks. It's Bastille Day which is such a shame. As a New Zealander it's a horrible feeling to experience as it is so alien."
She said she wasn't on the promenade when the truck ploughed through. "We got back just at the end of it ... As far as I'm aware we were two blocks away."
The teen marked herself as safe via a Facebook checking-in system that activates following a disaster.
New Zealand travel agent helloworld says it is in the process of ascertaining the safety and welfare of any clients that it may have in Paris or Nice.
"We are deeply saddened by these attacks. At this stage we have identified a few customers who may be in Paris or Nice at this time and we will be doing our best to contact them to ensure they are safe and /or they need any assistance with altering their travel plans," said marketing general manager David Libeau.
A Kiwi woman whose twin is believed to be in Nice says she won't relax until she hears her sister is ok.
Val Feisst, of Cambridge, has been waiting anxiously all morning for a Whatsapp message from her twin sister Enid Limmer, who left Hamilton for France to see the Tour de France with her husband a couple of days ago.
"I'm her twin sister so I just need to know she's ok," Feisst told the Herald.
She was feeling "a bit apprehensive," saying she wouldn't be able to relax until she heard from her sister.
The twins' other sister heard from Limmer last night New Zealand time, saying she was in Nice with friends and her husband and planned to spend the next day or two there before heading on to Paris.
"But I haven't heard anything in the last few hours.
"She's set up a Whatsapp texting thing - I'm keeping an eye on that. We just need to know she's alright."
In a message to Limmer, Feisst asked her to please contact her family as soon as possible.
"She has a daughter and a son over here and we all want to know."
Travelling Kiwis aren't however expected to be put off visiting Nice for long.
House of Travel commercial director Brent Thomas said the company was expecting a slowdown in bookings for the next six weeks, but Kiwis were a resilient bunch.
That was the typical response but long-term, the booking pattern should be back to normal by mid to late August if no further events happened.
House of Travel said those planning to travel to Nice in the next few days would be advised on a case-by-case basis.
The company would work with customers to alter their travel plans if need be.
Mr Thomas said if the customer wanted to change their itinerary, staff would work with suppliers to try to make that happen.
Staff were now contacting those already in Nice and ensuring their safety.