A fire at a water sports centre in Rock near Wadebridge is being treated as suspicious by police.
40 fire-fighters tackled the blaze which started shortly after 3am this morning.
Police have launched a joint investigation with the fire service. Investigators were on the scene this morning to try and establish the cause.
The road was closed at the junction of Rock Road and Bodmin Lane until 7.30am.
Anyone who has any information is asked to call police on 101 quoting log 84 of 25/07/13 or Crimstoppers anonymously on 0800 555 111.
The wooden building in Rock has been severely damaged.
A building surveyor will now decide whether or not it will have to be bulldozed.
More than 40 firefighters are tackling a fire at a water sports centre in Rock in Cornwall.
Crews from Wadebridge, Delabole, Bodmin and St Austell were called to the centre in Rock Road near the Slipway just after 5am.
The crews pumped water from the river to fight the fire.