Ludwig angina is a rare but potentially lethal infection of the submandibular space that can cause significant upper airway obstruction. We report a case of undiagnosed Ludwig angina that progressed rapidly to death. Ludwig angina was suspected after post-mortem computed tomography (PMCT) found swollen mylohyoid muscle with stranding in subcutaneous fat, thickening of deep fascia, and local lymphadenopathy. Subsequently, an autopsy revealed woody induration of the submental region and liquefactive necrosis of the mylohyoid muscle, confirming the diagnosis. It is likely that the dental abscess identified on PMCT was the source of infection. Multiple invasive medical procedures were performed on the subject by the ambulance crew prior to his death. PMCT assisted further in determining procedural success.