Michael Kilian 
Deepkill [EPUB ebook] 

After a botched terrorist plot, a coast guard agent uncovers a terrifying threat against America The plan is simple. The moment the Homeland Security adviser reaches the middle of the Chesapeake Bay Bridge, a team of suicide bombers will rush his car, killing him and destroying the bridge. But as the plot’s mastermind watches from afar, he sees only 2 small explosions. The bridge has survived; the plan has failed. He will have to find another way to bring terror to the United States—and he’s about to get a fearsome opportunity.   Investigating the attack, coast guard agent Erik Westman meets a dying air force pilot who claims to have dumped a nuclear bomb off the coast of Delaware in 1967. It’s still there under 30 feet of water, waiting to be used by anyone mad enough to detonate it. If Westman can’t reach the weapon before the terrorists, the nation’s capitol will burn.