Check out this wild video we obtained that captures the immediate aftermath of a fiery wreck along I-70 just outside of Denver Thursday morning -- where a tanker got slammed into by another driver on the road after it'd pulled over when it started to overheat.

Per state officials, another person who was behind the tanker somehow managed to slam right into it ... causing the entire vehicle to ignite and explode, with fire going everywhere.

That's where our video picks up ... seconds after the crash, and just moments before the flames shoot out onto the rest of the freeway ... with oncoming traffic not able to dodge it. The driver from this dashcam footage actually cruises right through ... but was freaked out.

You can tell the entire scary scene crept up on him out of nowhere ... and before he had time to react or swerve to avoid it -- he was right in the thick of the massive blaze.

Fortunately for him, he came out on the other side alright ... but it looks like the car in front of him -- which also went through the inferno -- had some lingering fire hanging on the tire.

Other videos of the accident circulated as the fire grew larger -- spreading to grassy areas on the side of the freeway and sending up plumes of smoke high into the sky -- and you can see just how big it was ... ultimately, parts of I-70 had to be closed off for much of Thursday.

Sadly, the person who rammed into the truck died ... and the tanker driver was hospitalized with non-life threatening injuries. No word on what exactly may have caused the crash.