An airline passenger tried to smuggle a gun hidden in a hollowed-out book at Honolulu Airport last year, the Transportation Security Agency reported this morning.

The gun incident, which occurred in March, was one 1,543 firearms discovered in carry-on bags at checkpoints across the country, the TSA reported on its website today.

The TSA said that amounts to a little over four firearms per day. Of those, 1,215 (78.7 percent) were loaded. Firearms have been found at a total of 199 airports with Atlanta on top of the list – 95 in 2012. 

The TSA said that 637,582,122 passengers in 2012, or around 1,746,800 a day.

In addition to the firearms, TSA officers found a live grenade, several different types of explosive devices, a grenade launcher and a watch resembling a piece of an improvised explosive device.