Ever the diligent worker, Syed Rizwan Farook had arrived first and took the seat at the head of the table. The tech-savvy restaurant inspector, 28, had taught his co-workers how to use some new computer programs and had won TGI Friday gift cards for his good performance.

Now they would play a game to win more gift cards. The 75 or so workers in the room were handed wireless clickers so they could answer yes or no questions on a big screen. Fun, true-or-false questions about one another at first, then training ones.

The woman delivering the clickers came to their table.

“Where’s Syed?” someone asked.

His jacket still hung from the back of his chair.

They told her to just to leave the clicker there — he would be back.