No BBQ allowed. Any thought on how I should respond are welcome?

I received this pleasant email today:



I got a report from other tenants in the building that there was a BBQ in the parking lot with alcohol being consumed today.  Alcohol or not, this is an office building and both of these activities are inappropriate for a professional setting.  Other tenants have clients coming to the building and this is not something that should be going on.  If people need to be involved in an activity like that there are parks nearby that can be used.  The report that I got was that it was your office that was doing this.  If this is true please contact the people on site and make sure this does not happen again.






There are a number of responses to this email that I can think of....but I'm not sure yet what the best one is yet. Any thoughts of how I should respond?