Fire has gutted two rooms on the top floor of the Pacific Hotel. (ABC News/Supplied)

Pacific Hotel staff and emergency services evacuated all guests as the flame spread. (ABC News: Jemima Burt )

Fire is being extinguished at the Pacific Hotel, a COVID-19 quarantine venue, in Cairns, Australia November 28, 2021 in this picture obtained from social media. Sarah Orton/via REUTERS THIS IMAGE HAS BEEN SUPPLIED BY A THIRD PARTY. MANDATORY CREDIT. NO RESALES. NO ARCHIVES.

Smoke billows over the Pacific Hotel, a COVID-19 quarantine venue, in Cairns, Australia November 28, 2021 in this picture obtained from social media. Sarah Orton/via REUTERS THIS IMAGE HAS BEEN SUPPLIED BY A THIRD PARTY. MANDATORY CREDIT. NO RESALES. NO ARCHIVES.

Police have charged a woman with arson after a fire destroyed part of a Covid-19 quarantine hotel in Cairns City on November 28, 2021. Twitter.com/@QldPolice

It is not clear why the woman allegedly lit a fire under a bed in the hotel room. REUTERS