Mars Incident

The Mars Incident were various incursions leading up to a large scale demonic invasion of Mars in around 2145.

Background
Mysterious occurrences involving UAC facilities have everone on high alert. Not much is known about the classified incident on Mars, but containment is becoming more difficult.

According to known details that the UAC released, some kind of accident occurred, which caused some form of explosion, leading to a catastrophe. The mysterious incident shut down the UAC base on Mars. Many men and women were lost, and there are no known survivors, and UAC tried to cover up the details of the events. Burying details so deep that no one was able to find out anything.

It refers to the initial invasion by demons after initial teleportation experiments in Doom Resurrection (June 2145) that was initially covered up by UAC, the larges scale one in Doom 3 (November 15, 2145), and the one at Mars Outpost (Doom RPG) caused by Dr. Kronos in late 2145 not long after the events of Doom 3 (late October or December). It apparently refers to all of them (though the events are only known about in hushed rumors, as UAC covered up most of the information).

Records claim there were no known survivors, but most details of the incident were covered up by UAC command.

There is in fact at least one survivor who went on to stop other Demonic incursions, an unnamed Marine (B.J. Blazkowicz).

Behind the scenes
Like Doom 3, the events of this game roughly mirror the events of the Doom II backstory about the UAC Mars Base invasion as mentioned in the game's manual. Perhaps the escape mentioned in the Doom II manual, might explain what happened to B.J. Blazkowicz folloing the death of everyone else in the base.

Both the game and the comic are exceptionally vague about what is considered the Mars Incident. There are almost no direct references to Doom RPG, and its made clear that Stan is not the same character from Doom RPG, or Doom 3.

Similar events occurring all over Mars according to both Doom 3, Doom Resurrection, and Doom RPG (but roughly only a few weeks or months apart).

Both events of Doom RPG/Doom 3 can be described similarly. The intro for Resurrection of Evil refers to destruction of the UAC Mars Research Base in much the same way Doom II RPG comic describes the Mars Incident: "We were told there was some kind of explosion that caused a catastrophe, no known survivors and UAC tried to cover up the details of the events." Resurrection of Evil describes that the base suffered a cataclysmic mechanical failure during a classified research experiment, resulting in total destruction of the facility, but adds that their was only one survivor located. The Lost Mission and Doom Resurrection, however, show that there were other survivors as well. Sam, a drone bot from Doom Resurrection's final level, is also covered in Doom II RPG, connecting the events together.

Doom Resurrection's final ending cutscene refers to events of that game as the Incident at Mars Research Facility (Mars City) (this initial event is alluded to by references to Garrett and Sam in Doom RPG II).