The woman was arrested by officers from Bray Garda Station yesterday morning on suspicion of reckless endangerment and can be held for up to 24 hours before being charged or released.
Brian Murray, 46, and Mark O’Shaughnessy, 26, were killed when the roof of a disused factory on Lower Dargle Road in Bray, Co Wicklow, collapsed on them on September 27, 2007.
It is the second arrest in a little over a month into the incident as part of an investigation by Gardaí, and the Health & Safety Authority into how the two firefighters died.
A man in his 40s was arrested last month in relation to the incident but was later released without charge, while a file was being prepared for the Director of Public Prosecutions.
The families of the dead men appeared before an Oireachtas committee earlier this year and called for an independent investigation into the fire. They have privately engaged a Glasgow-based firm of fire investigators to investigate and carry out a report on the blaze.