Police are investigating a fire at the Trecarn hotel in Torquay, which is believed to have been started deliberately.
Over 120 guests were evacuated from the property, which is operated by Britannia hotels, on 25 September and no one was seriously injured.
Firefighters responded to a call just after 11:30pm on the Sunday night and requested support from the police and ambulance service soon after.
Detective Inspector Dave Pebworth said: “A major response from Devon and Somerset Fire and Rescue ensured that this fire didn’t have fatal consequences, but a serious amount of damage and disruption was caused and those responsible must be identified.
“Following advice from fire investigators, it is believed that this fire was started deliberately, and police are appealing for witnesses.
“We would like to hear from anyone who was in the area and saw anything suspicious between the times of 10:30pm on Sunday 25 September, and half past midnight on Monday 26 September.”
Britannia Hotels operates 61 hotels across the UK, with over 10,000 bedrooms.
Anyone with any information is asked to contact 101 101@dc.police.uk quoting crime reference CR/089139/22.
Information can also be passed to Crimestoppers anonymously on 0800 555111 or online at www.crimestoppers-uk.org.