The tsunami strikes the coastline and begins its run of devastation.
We're treated to the obligatory scenario of New York City being destroyed.
In the streets, hundreds of people abandon their cars, grab their things, and try to flee, but are very quickly overtaken by the tsunami.
The final shot shows the city immersed underwater save for the very tops of the World Trade Center; the broken-off head of the Statue of Liberty, surrounded by cars and dead bodies, bouncing like a dropped basketball down Wall Street.
On the Virginia coast, people have abandoned their cars, racing pell-mell about in all directions, screaming frantically in a mad rush for higher ground. A few simply stand outside their cars and wait to perish.
Among them are Chuck and Vicky Hotchner, holding and stroking each other for a final moment of comfort as the tsunami approaches. Leo and Sarah are part of a small crowd that have gotten off the road, racing for higher ground among the hills.
The Messiah has made final preparations for their interception of the Wolf Comet. The crew members have asked for their families to be brought to the Mission Control Center in Houston so they can say final goodbyes. Baker's husband and daughter, and Simon's fiancée are on standby. But Commander Monash's wife is still en route and hasn't arrived yet. Fish's two sons were on active Naval duty and couldn't be reached. Accepting this, Fish gives a quiet prayer to his late wife, saying he's coming home to her at last.
Baker and Simon say their final goodbyes tearfully. Transmission is just about to be terminated when officers come rushing to the control room with Mariette Monash in tow. She reaches the control room in the nick of time, holding her baby son, who she's named Oren in her husband's honor. Commander Monash, although still blind, can hear Mariette and Oren Jr. He gives them an emotional farewell as Col. Tulchinsky sets the warhead timers and Baker and Fish calculate trajectory for the final interception run.
They say farewell to each other; Baker closing her eyes and Simon closing his as Captain Tanner flies the Messiah through the vent into the comet's interior. The warheads detonate, shattering the Wolf comet into millions of tiny fragments.
Leo, Sarah, and Sarah's baby sister are among a group of several dozen people that have gotten to the top of the highest hill they could find, barely escaping the tsunami. They watch as the shattered fragments create a firework-like light show in the sky.
Deep Impact closes with President Beck delivering an impassioned speech to a huge crowd in Washington D.C. sometime later, after the waters of the Atlantic Ocean have receded and settled back into the ocean basin.
Acknowledging the incalculable losses of lives in America, South America, Europe and Africa, President Beck tells his people that they must remember those who died for them, and carry on with their rebuilding of the human way of life. The camera pans out for the final shot showing the U.S. Capitol building under reconstruction as the people gathered there cheer.