Rep. Gabrielle Giffords and many others were shot at a "Congress On Your Corner" event. I'm not going to discuss this senseless shooting, but wanted to give background on Congress On Your Corner events.
Congress On Your Corner is a smidgen different from a town hall in the people that attend them.
MANY members of Congress do Congress On Your Corner events. Rahm Emanuel was famous for doing them when he was a congressman. He frequently did them at supermarkets throughout his district. Supermarkets were ideal because they were convenient for constituents and allowed a member of Congress to come into contact with a cross-section of voters in the district, not just the activists who show up at town hall meetings.
After 2006, one of Rahm's responsibilities was helping the freshmen elected that year get re-elected in 2008. He and others encouraged freshman members (and anyone else who is in a competitive district) to do Congress On Your Corner events. It didn't have to be supermarkets, though. For example, Patrick Murphy did some at regional rail stops in his district. A location that was convenient to voters would allow members to maintain a certain level of accessibility. They're best done in urban and suburban districts.
(Members representing rural districts have in-person events as well, but you might see more tele-townhalls in rural districts given the ground that you have to cover. A robocall would go out to voters throughout the CD, and if you stayed on the line, you can participate. They've been done through official offices and campaigns. Tele-townhalls can be ridiculously controlled and just isn't as good as face-to-face interactions.)
Congress On Your Corner is a valuable way for members of Congress to take the temperature of their district and talk to constituents. Caseworkers from the official office are also on hand (as was the case in this Giffords event) to work on constituent services.
I would understand if members of Congress did in-person events less frequently or stopped doing them altogether, but our representatives need ways to come into contact with those outside the bubble. They're better representatives when they do.