A Central Districts Police spokesperson said all serious and fatal crashes required comprehensive investigations.
"It's too early to determine exactly what may have caused this crash and until that investigation is complete police will not be speculating on any aspect."
Earlier reports said Ms Hurley was the designated sober driver of a car returning from Palmerston North. Also aboard were her partner Chaise Leslie and two other friends.
Mr Leslie was airlifted to Palmerston North Hospital where he was reported to be in a serious condition yesterday.
Another passenger, Hamish Kennedy, 25, was admitted to Whanganui Hospital's intensive care unit with broken ribs and sternum, while a third friend was airlifted to Wellington Hospital with serious injuries. No update on their conditions was available at press time.
All three were trapped in the wreckage until Whanganui Fire Service crews were able to cut them free.
While Ms Hurley and Mr Leslie were life partners, they were also business partners and owned and operated Maggies Pies in Cross St, Castlecliff.
A worker at the nearby service station, who did not want to be identified, said the couple had been in the pie shop "for a year or two". "They were a really nice couple. They'd get their bread and other stuff from us.
"This is really shocking news. Everyone knows everyone else in this little shopping area and everyone will be feeling this. It's very, very sad."
Ms Hurley's friends and family have posted tributes on Facebook, all of them remembering a "beautiful young lady".
One said she could not believe Ms Hurley was gone.
Taylor Rhodes wrote: "You were so beautiful inside and out, it's scary how things can just change in seconds and even minutes. Rest easy Emily and Baby Jake. xxx ... "