The 35-kilogram rover dropped 4.2 metres into a dry brick cistern at a former writer’s home in Karrada on Tuesday, after its mapping system directed it across a section of timber floor shown as solid. No one was hurt, but the floor was damaged and the site was closed. The machine’s fall exposed a flaw in software used to build digital models of historic buildings.
Kailee Weissnat, technology director at mapping firm Rafid Span, resigned at a briefing on Wednesday, hours after the incident became public. “The model gave a false room the confidence of a measured one,” she said. A three-year contract worth IQD 18 billion (about €12 million) is now under review.
A phantom chamber on the map
The house, a two-storey residence in Karrada associated with the fictional travel writer Agnes Cresswell, was being prepared for a digital heritage archive. The software had marked a 38-square-metre chamber beneath an upstairs room. Investigators say the supposed space was actually a pattern of echoes created when the scanner’s readings of a carved arch were joined to an older scan taken from another angle.
The rover was sent to verify the mapped space with a close-range floor scan. At 10:17 on Tuesday, its front wheels crossed the weakened boards and dropped through. A site caretaker and two engineers were in the building but in a different room; they heard the impact and found the rover lodged in the cistern below.
“We were told the route was safe because the software had drawn a floor where there was only a void.” — Z. Miller, Baghdad Heritage Survey Office
The office said the system had been used to map 94 buildings since January, including libraries, courtyard houses and government archives. It has suspended autonomous floor checks at all of them. Manual inspections have already found six unrecorded cavities at 14 sites checked so far, though officials say none is currently judged at risk of collapse.
The error travels beyond one house
Yolanda Munyai, a structural engineer advising the city, said the fault was not simply a weak floor or a misjudged route. “The machine followed the map it was given,” she said. “The danger is that a clean, convincing model can make people trust a result that has never been physically confirmed.” She has called for every scan used to guide equipment to be checked on site.
Rafid Span says it has disabled the feature that joins scans from different dates and is rebuilding the house model from fresh measurements. The company has not said how many of its other models used the same setting. Officials will decide next week whether the archive project can resume, while the house remains closed for repairs and a separate floor-by-floor inspection.
