Everybody shudders when a fan runs onto a baseball field and lurches at an umpire. Only Kevin Hallinan can do something about it.

So before the sun had even risen in San Francisco on Wednesday morning, baseball's senior vice president for security and facilities was on an airplane bound for Chicago to investigate Tuesday night's incident at U.S. Cellular Field.

"We owe it to all the players and umpires to do a better job," Hallinan told ESPN.com before boarding his flight. "We have a responsibility to keep them safe on the field. We didn't get that done Tuesday. We've got to find out why."

Hallinan said his early read on Tuesday's incident was that the fan who attacked first-base umpire Laz Diaz had gotten caught up in "a copy-cat situation." Three fans had run onto the field in the previous two innings -- to wild cheers from the crowd. And those situations tend to feed on themselves.

So Hallinan said he intended to focus initially on what could be done to stop fans from being in position to get onto the field in the first place.

"We've got a look at the access (to the field) of people coming down the aisles," he said. "We've got to address what we call 'ticket discipline.' Anybody that gets that close the field needs to be stopped, and a ticket needs to be shown. We've got to be more alert in that area."

An incident of this magnitude would be a high priority for baseball no matter where it happened. But this particular incident occurred in the same park where Royals first-base coach Tom Gamboa was attacked in September, and in the park that will host the All Star Game this July. So baseball figures to be extra diligent in dealing with this situation.

"The commissioner has given us carte blanche to get it done," Hallinan said. "That's what's critical here. The White Sox are obviously very, very upset. They work hard. They've got good security people. So we'll huddle with all of them and get right to work."

No one wants armed guards lining a baseball field. No one wants German shepherds snarling at fans in the field boxes. No one wants to see beer sales banned completely. But baseball will look at everything -- because this can't happen again.

"Unlike hockey, we have no barriers around the field," Hallinan said. "We can't do that. So we're looking to learn from this. What happened happened. And we're going to do everything in our power to make sure it doesn't happen again."

Jayson Stark is a senior writer at ESPN.com.