French prosecutors have ruled out deliberate criminal action in the April fire that destroyed the roof and spire of Notre Dame cathedral, but are investigating possible negligence.

After two months of preliminary investigation, the Paris public prosecutor’s office announced on Wednesday that the initial inquiry into the fire at the Notre-Dame-de-Paris has been completed, and that “no element” of their investigation backs the hypothesis that the blaze was of criminal origin.

The two-month preliminary investigation was conducted by the Criminal Brigade of the Regional Directorate of Judicial Police, which undertook about 100 witness hearings and assessed numerous findings, resulting in a file of 1,125 documents.

Paris prosecutor Remy Heitz said on Wednesday that “several hypotheses are being considered by investigators, including that of a malfunction of the electrical system or that the fire was caused by a badly extinguished cigarette” but said that it was not possible to say with certainty at this point what was the cause of the fire.

However, the Paris public prosecutor’s office opened a judicial inquiry into “involuntary damage caused by fire, by manifestly deliberate violation of an obligation of caution or security” according to Le Figaro, with the magistrates having powers to investigate anyone responsible for negligence.

The April 15th fire had destroyed the UNESCO world heritage site’s roof, spire, and parts of the vaulted ceiling, with many fearing on the night of the incident that if the blaze had reached the towers — which house the cathedral’s iconic bells — the whole structure was at risk of collapse. Firefighters fought through the night to save the main structure of the building including the towers, flying buttresses, and rose window.

Donations Reach €1Bn to Rebuild Notre-Dame Which Was ’30 Minutes’ Away from Total Destruction https://t.co/Zyr7yREahH — Breitbart London (@BreitbartLondon) April 17, 2019

Since the fire, between 60 and 150 workers are on the site daily, continuing to remove the rubble and stabilise the structure, with efforts to secure the building set to continue for the next few weeks.

For the first time since the fire, a mass was celebrated in Our Lady on June 15th by a small group of people, mainly priests and other church staff and officials, all donning hardhats as a safety precaution.

President Emmanuel Macron has promised that the monument will be rebuilt within five years. However there has been concern that architects may attempt to modernise the gothic structure, with designers floating ideas within days of the fire that the rebuild should include a glass roof, steel spire, or even an Islamic minaret. In response, the French Senate voted in late May to mandate that the work must be traditional and that the spire must resemble “the last known visual condition” before the fire.