One of the Car Talk brothers (the one with the laugh):

Tom Magliozzi, one of public radio’s most popular personalities, died on Monday of complications from Alzheimer’s disease. He was 77 years old.

Tom and his brother, Ray, became famous as “Click and Clack the Tappet Brothers” on the weekly NPR show Car Talk. They bantered, told jokes, laughed and sometimes even gave pretty good advice to listeners who called in with their car troubles.

If there was one thing that defined Tom Magliozzi, it was his laugh. It was loud, it was constant, it was infectious.

“His laugh is the working definition of infectious laughter,” says Doug Berman, the longtime producer of Car Talk. He remembers the first time he ever encountered Magliozzi.

“Before I ever met him, I heard him, and it wasn’t on the air,” he recalls.

Berman was the news director of WBUR at the time.

“I’d just hear this laughter,” he says. “And then there’d be more of it, and people would sort of gather around him. He was just kind of a magnet.”

The Magliozzi brothers grew up in a tough neighborhood of East Cambridge, Mass., in a close-knit Italian family. Tom was 12 years older, the beloved older brother to Ray. They liked to act like they were just a couple of regular guys who happened to be mechanics, but both of them graduated from MIT.