Airtight Bridge is a steel bridge spanning the Embarras River in Coles County, Illinois, 8 miles north of Charleston, Illinois.

Airtight Bridge was like most rural bridges for decades… A place for kids and drifters to drink and swim, but on October 19th, 1980, the bridge was the site of a truly disturbing discovery. Two men saw a body just 50 feet up the river, but something wasn’t right. The woman’s nude body had been brutally mutilated- no head, no hands, no feet. Nearly a year after her discovery, the unidentified body was laid to rest in Charleston’s Mound Cemetery under the name "Jane Doe." Those who remembered the case occasionally traveled to her grave and left flowers or other tokens of their sympathy. Finally, in 1992, 12-years after the discovery of the body, there was a break in the case. On November 20, the Sheriff’s Department held a press conference in Charleston, this time to announce that the identity of the Airtight victim had been discovered. Her name was Diana Marie Riordan-Small, a resident of Bradley, Illinois, who disappeared from her home a short time before her remains were found over 100 miles away in Coles County. The revelation was the result of cooperation between Coles County Sheriff’s Detective Art Beier and Detective Steven Coy of the Bradley Police Department. Slowly but surely, a picture of what happened to Diana Small began to emerge.

The reason that no one who matched the description of the body found at Airtight turned up in the missing persons reports was that Diana was never reported missing. "Her husband… told police he wasn’t all that concerned because Small had left home on occasions before," the Journal Gazette reported. Furthermore, Diana’s mother and sister had joined a small Christian sect before moving west, where they became disconnected from Diana and her husband. After nearly a decade, her sister, Virginia, left the church and moved to North Carolina. Virginia decided to get in touch with the rest of her family and learned of her sister’s disappearance, at which point she filed a missing persons report. According to Dave Fopay of the Journal Gazette, "Detective Art Beier saw the report on a national listing, realized Small’s descriptions matched that of the Airtight Bridge victim and contacted Bradley police."

In October 2008, the anonymous headstone that had marked the grave of Diana Small was replaced with one bearing her name. With the laying of a new monument, this chapter of the Airtight Bridge murder came to an end, but the family of the victim and the few who refuse to give up the pursuit of justice will never forget. Those rusted, burgundy trestles that span the Embarras along that winding road in rural Coles County will always elicit a tingle along the spines of visitors, as well as a supernatural sense that something very wrong happened there.

The killer, however, remains a mystery. Today, people who use the bridge claim there’s an odd stillness that creeps around it. Perhaps the murderer threw her body off this bridge and returns from time to time to reminisce about his murder or, even scarier, to do it again.