We were all in the car, taking Jared to school when we spotted the police cars at the high school a couple of blocks away. A dozen of them, perhaps more. We would have been concerned, had we not seen the large highway signs saying "Police Training in Progress". It turns out that training was about school shootings, a la Columbine or Virginia Tech.

Officers responded to a 9-1-1 call about the mock incident where two intruders were shooting students at St. Ignatius College Preparatory, a local private high school. Wearing full tactical gear, officers entered the school to find "dead" students in the lobby. A suspect appeared and began firing at the police; they returned fire. And so it continued, for more than two hours of realistic mayhem.

Simulations such as these are designed to give emergency personnel practice and experience in dealing with a situation that we all hope never happens. They can also help identify areas where the planned response to such an incident may need to be changed or improved. "We try to make these scenarios as real as possible," said Fire Chief Joanne Hayes-White. Of the need for such drills, "it's definitely a sign of the times," Hayes-White said. "It's dealing with reality, unfortunately. We know we'll be better prepared if it happens."

Not everyone wants to be involved, however. San Francisco's public school system does not participate. "There are students in our schools who have been through a great deal of trauma either in other countries from where they immigrated or right here in San Francisco," said district spokeswoman Gentle Blythe, and the district doesn't want to subject them to any more, even if it isn't real.

I think drills such as this one are important so that officers can have first hand experience with such possibilities and so that officials can hone and fine-tune their emergency plans. Still, I'm not sure I'd want my kids involved, although I'd most likely allow it. Would you?