• Starbrand (Ken Connell) – a young aspiring superhero and native of Pittsburgh bearing a mysterious sigil granting him potentially infinite power. Though the instigator of the Pitt, his presence in the story is limited, appearing in only a few panels without dialog or being named.
• The Witness (Nelson Kohler) – a man who went into a coma precisely when the White Event occurred and subsequently died. His intellect reincorporating as a ghost-like psychic projection, he cannot be seen or heard, neither can he interact physically with the world in any way, but he can travel anywhere at will to observe events. He is compelled by a strange pull to witness people manifesting paranormal abilities.
• MacIntyre (Mac) Browning – Colonel in the Army's Defense Intelligence Agency called in to assess and handle the situation.
• Jenny Swensen (Spitfire) – government agent and operator of the M.A.X. Armor, which is used to investigate the scene and try to rescue survivors.

The storyline of The Pitt begins in issue #12 of Star Brand. In the previous issue, Ken Connell used his power to become the world's first costumed superhero. Now enjoying growing fame, he makes an appearance at a local Pittsburgh comic-book convention. A recurring enigmatic foe known only as the Old Man ambushes Connell at the show, destroying the building and killing hundreds of by-standers. After escaping, Connell realizes that he was able to read the Old Man's mind during the encounter, and thus learned that he is a centuries-old human bearing a brand like his own who was driven insane by it. Fearing the same thing may happen to him, Connell resolves to rid himself of the star brand immediately by flying to the far side of the Moon and dissipating as much of its energy as he can. However, as he begins the flight he has second thoughts about possibly being stranded so far from medical aid if anything should go wrong, and instead deems that ten miles (16 km) above the Earth is far enough. The issue ends with a splash page depiction of a massive ball of light erupting from Ken Connell.

The destruction of Pittsburgh occurs at exactly 6:06 pm Eastern Standard Time on December 22, 1987. The spontaneous release of the Star Brand's energy instantly and silently annihilates all matter in a massive spherical volume, 50 miles in diameter, centered ten miles (16 km) above ground level. The sphere's intersection with the ground creates a perfectly symmetrical concave crater in the Earth's crust 15 miles (24 km) deep (exposing the hot mantle). The entirety of Pittsburgh, its immediate suburbs, and the nearly half a million people within cease to exist. As the atmosphere rushes into the sudden vacuum, creating violent winds several times greater than hurricane strength, thousands more are killed in neighboring areas.

The abrupt silent flash of white light can be seen for hundreds of miles, but with the immediate cessation of communication from the area the nature of the event is unknown. The federal government sends in a military reconnaissance team led by Colonel Browning to assess the situation, assisted by Jenny Swensen and her Spitfire robot suit. Faced with the enormity of the disaster and the possibility of it being a Soviet strike, Browning institutes a severe security lockdown, ordering Swensen to abandon attempts to rescue survivors and shooting down a news helicopter. Swensen ignores Browning's orders and retrieves a car holding a family who were pulled into the crater by the winds and were slowly sinking into the mire of debris and liquid accumulating in its depths. During the rescue, some of the "Pitt Juice" seeps through her armor and impairs her systems. When she returns, Jenny learns of Browning's increasingly paranoid attempts to lock-down all information. She abandons Browning to try to help as many people as she can, and is threatened with summary execution for doing so. However, her search proves fruitless, and Browning allows her to return without incident after conceding that the tragedy is beyond the military's ability to cover-up, or indeed human society's ability to comprehend.

Parallel to the main storyline, the Witness observes the unfolding of events, from Ken Connell's initial cause (which he mourns being unable to prevent) and a possibly hallucinated encounter with the vengeful souls of all those who died in the Pitt. At one point, Jenny Swensen sees and attempts to communicate with him, one of the few times a living person has been able to do so.

The crater itself is referred to as The Pitt, as is the event that created it. Within the fictional universe, it is occasionally also referred to as The Black Event (in contrast to the earlier White Event which first created paranormal individuals).

The destruction of Pittsburgh (and the unsolved mystery of its cause) lead to a dramatic rise in international tension and a vast militarization of American society, including the suspension of some civil rights. Many cities suffer dramatic drop in population as residents fear becoming victims of another "Pitt". New York and surrounding areas in particular suffer severe economic downturn as, in addition to general depopulation, ash and smoke drifting Eastward from the Pitt have a negative environmental impact.

The Pitt led into the following mini-series The Draft and then The War, and ultimately the conclusion of the entire New Universe.

• The Pitt on Marvel Database, a Marvel Comics wiki