Visitors to the site for several hours Friday ended up seeing an image of a dancing banana and a brief text message directed against an officer with the city's police force. There has been no comment from police.
In a release Saturday, the city says it is "confident that no corporate or resident information was compromised as a result of the breach."
It adds that the "issues were related to a third party service provider" and that the site is now back up.
An online message purported to be from loose-knit hacking group Anonymous is taking credit for the attack.
A city spokeswoman says police are investigating.