A statement of affairs lodged at Companies House by administrator Leonard Curtis revealed the scale of debt following the collapse of the firm which had been in business since 1970 providing structural engineering services including 3D building design, structural steel fabrication and erection.
The document shows nearly £1m was owed to subcontractors and suppliers who have been left holding now worthless invoices.
Killelea also owed £1.1m to employees and directors and £1.7m to its main financial backer.
Leonard Curtis said the firm’s turnover dropped dramatically to £11.4m in 2022 from £22m as jobs dried-up and cash flow was hit further by a disputed payment on a major job.
One of the company’s highest profile recent projects was the £20m new Luton airport car park which hit the headlines in October when it caught fire.
Killelea worked for recently collapsed main contractor Buckingham Group on the Luton job.
