Six Nations firefighters say they suspect a fire at an abandoned building in Ohswekenan was arson.It happened on 1073 Seneca Road at around midnight last night. Officials say the blaze started in a SUV at the back of the building and spread to the west end of the structure. Last year, there were more than 20 structure fires in Six Nations. Many of those fires were in abandon buildings, and many were considered suspicious. The Office of the Ontario Fire Marshal has been called to consult on the investigation.