A BUSINESS OWNER'S DECISION to recognize a labor union is almost always a private matter. But if those employees happen to be responsible for the safety and security of the tens of thousands of people who daily go to work or do business in or near high-rise office towers, then that decision is important to all of us —and Mayor Antonio Villaraigosa's intervention is justified. That's the case with real estate mogul Robert Maguire's decision, announced Tuesday, to fund a training program and begin contract talks with the security officers who guard his properties.

It was Maguire who six years ago broke through the acrimony between building owners and janitors with his backing of the "Justice for Janitors" campaign, putting pressure on other property owners — who quickly fell in line. For the last several years, though, Maguire rejected efforts by the same union to organize security officers, arguing that it's a bad idea for unionized guards to leave their posts when a building's janitors go out on strike.

Leave it to Villaraigosa to put the two sides together to work out their differences by agreeing to a new security-only union. This is exactly the kind of behind-the-scenes brokering that voters believed Villaraigosa, with his labor background and his big-business supporters, could deliver. Soon after his election, he helped head off a potentially crippling hotel workers strike, and now he deserves credit for helping to ensure that security officers — in Maguire's buildings, at least — will be professionally trained in stable jobs that have historically high turnover.

The agreement between the new union and Maguire is not just a good deal for the guards and their families. In the event of a fire or other disaster, the man or woman in uniform at the front desk is the first responder and should be expected to know the evacuation plans. Firefighters, police and paramedics should be able to rely on them to know the best way in, up, around and out of the structure.

Union organizers, of course, hope that after Maguire's move, other owners will sign on with alacrity. They want the county's estimated 10,000-plus security officers to have better pay and benefits, and they want to return the workers, mostly African Americans, to the ranks of immigrant-dominated organized labor. That's for labor and management to work out. But safety and security are matters that concern all of us, and Maguire's move — with the mayor's help, and with some follow-up by other high-rise owners — means we all may soon be a little more secure.