Since retiring from rugby in November 2015, McCaw has worked for Christchurch helicopters after earning a commercial helicopter license
. He was called to action at the earthquake's epicenter in Kaikoura after being woken during the early hours of Monday morning.
"We got asked to ferry some USAR [Urban Search and Rescue] guys up first thing, so a couple of helicopters went up," McCaw, 35, told CNN reporters. "I took the fire guys up just to make sure everyone was OK in the houses and the roads that were stuck there."
Aftershocks from the earthquake have continued to afflict the area surrounding Kaikoura, causing landslides and fissures in the north of New Zealand's south island. Thousands have been left stranded
near the earthquake's epicenter.
The double World Cup-winning captain witnessed the damage first-hand and noted the impact on the surrounding landscape.
"The actual township's OK but the roads in both directions -- there's slips and stuff all over the place," said McCaw.
"I'm no expert but it's going to take a fair while to shift all that rubble to get cars or trucks in or out. It's going to be pretty isolated for a while.
"There's a few houses that are pretty damaged, and just the sheer size of the dirt and rock that's come down; railway tracks have been pushed out [of line] -- things like that which have been pretty amazing.
"And one of the things in Kaikoura is that the sea bed's been pushed up half a meter which is pretty noticeable. It shows you the power of the thing."
McCaw captained back-to-back World Cup victories for New Zealand in 2011 and 2015 and has been voted world player of the year three times. With 145 caps, he is the most capped international rugby player of all time.
On Sunday, New Zealand was the standout nation at the World Rugby Awards
. Fly-half Beauden Barrett was voted player of the year and Steve Hansen coach of the year for the fourth time in five years.
After going a record 18 games unbeaten earlier this year, New Zealand was also awarded team of the year.