People on the scene tried bravely to free at least one man who survived the impact of the crash, but were beaten back by the flames.
Tourists on board the Explorer Tourlines bus were helped out of windows of the vehicle, after its door was wedged shut.
The 16 people on the bus avoided any serious injuries.
Explorer Tourlines owner Stephen Cook said on Friday that the area where the crash happened was well known to be a dangerous stretch of road.
Earlier this week Lamb said: "This is a horrific incident that has impacted a large amount of people and that of the Te Anau and Milford communities."
Invercargill's Jakob Frazer, 17, arrived with a colleague moments after the crash.He said he saw an arm coming out of the passenger door, and a man was screaming for help.
He helped those around him before trying to help the car's driver.
When he arrived the car and bus were not on fire.
But after about 10 minutes smoke started coming from the car. Attempts to put out the fire with an extinguisher were unsuccessful and within minutes car and bus were in flames, he said.
Te Anau Volunteer Fire Brigade chief fire officer Graeme Moffat said the crash scene was 32 kilometres from Te Anau and the fire was "well-involved" by the time they reached wreckage.
Police have been working with Victim Support and wider groups to provide assistance and support for those involved in the crash.
