Firefighters say cloud over Salesforce Tower was steam, not smoke

SAN FRANCISCO (KGO) -- Steam that came out of the top of the Salesforce Tower early this morning created some concern from the public.

Several people thought the steam was smoke, but firefighters quickly determined that was not the case. Firefighters say the steam was caused by an AC unit that was venting.

Salesforce released the following statement: "The condensate seen was from the start up process of the building systems. This happens regularly and whether you can see it depends on how clear the morning is."

Firefighters thanked "the alert public who called 911 to report."