A police spokeswoman said emergency services were notified at 10.10am of a car towing a caravan had rolled on State Highway 57, between Te Rohenga Road and Heights Road.
"Both lanes were initially blocked and the shoulder of the road was being used as a single lane for diversion.
"One occupant of the car was reported to have sustained serious injuries.
"It looks like the car and caravan were removed at 11.35am and the road was being swept as a final clean-up. At 11.55am both lanes were reopened."
Murphy said his first thoughts were with his employee after he saw photos showing the caravan "completely obliterated".
He said he couldn't help but wonder whether he could have done something to prevent the accident.
"You think to yourself 'was there anything I could have done?' But the vehicle was near new and the caravan had just had a complete refurbish."
The 2017 Toyota Hilux and catering caravan belonged to Baxter's Catering from Porirua and had recently undergone a $16,000 refurbishment at Gypsy's Caravans in Levin.
Murphy said Anongnuch was a competent driver and the Hilux was purchased new in December 2017. It had done around 40,000km.
Another Baxter Catering caravan driven by Sam Donaldson was following and came on the scene soon after the crash, while another food caravan from The Mussel Kitchen was travelling in the convoy and stopped also.
The caravans were travelling from the cricket at the Basin Reserve in Wellington recently to set up for Nitro Circus in Napier.
The catering company was also preparing for the Homegrown Festival in Wellington.