A malfunctioning warning siren interrupted sleep for many residents on Madison’s southwest side early Monday. That siren started going off at about 5:00 A-M. The Dane County Emergency Management office says it was a simple malfunction. There was no tornado in the area — even though the weather was stormy at the time. County officials say maintenance is done on all of the sirens, but they can still malfunction. Workers with the agency shut the siren down for a few hours Monday, fixed it, then brought it back online.