“Patriots Day”

***

(R, 2:13)

Whether they are celebrated filmmakers or ordinary folks, tragedy can bring out the best in people, and “Patriots Day” is the latest example of both sides of the equation.

An effective, efficient and quite dramatic examination of the events surrounding the 2013 Boston Marathon bombing that killed three and injured 264, “Patriots Day” is a tribute to people who earned it: the investigators and first responders who ensured that a horrible situation did not become even worse.

Following “Deepwater Horizon” and its exacting look at 2010’s drilling rig explosion in the Gulf of Mexico, “Patriots Day” is this year’s second successful disaster-describing film for director Peter Berg.

In both pictures Berg is helped considerably by the presence and performance of Mark Wahlberg in the starring roles. A native of Boston who brings that city’s reality with him to “Patriots Day,” Wahlberg excels in a part that was created around his strengths.

Berg also helped himself by allowing a welcome restraint to modulate his direction, keeping things moving briskly in classic police procedural fashion and, if not totally avoiding overly emotional moments, downplaying them as much as possible.

There is, of course, true sadness in this film as well, not only because of the amount of mayhem involving innocent people it depicts but because it is difficult to watch without a sense that things are not over, without acknowledging that another, similar event could be as difficult to prevent as this one was.

One of the intriguing ironies of “Patriots Day” (written by Berg, Matt Cook and Joshua Zetumer) is that while much of it tries to be as accurate as possible, Wahlberg’s character, salt-of-the-earth Sgt. Tommy Saunders, is not an actual person but a good-hearted composite of several Boston police officers.

“Patriots Day” begins with the sergeant working a tough case and aggravating a knee injury in the process. Boston Police Commissioner Ed Davis (John Goodman) tells him he’s going to be working the Boston Marathon finish line the next day, an assignment, he tells wife Carol (Michelle Monaghan), he loathes because he’ll have to wear the bright orange safety vest he calls “the clown suit.”

Before the race begins, “Patriots Day” checks in with the varied cast of characters whose experiences the film will focus on after the bomb goes off. Specifically:

>> Young marrieds Jessica Kensky (Rachel Brosnahan) and Patrick Downes (Christopher O’Shea), who plan to visit the finish line as a lark;

>> MIT campus policeman Sean Collier (Jake Picking), introduced flirting with a comely young scientist;

>> Chinese entrepreneur Dun “Danny” Meng (Jimmy O. Yang), proudly showing off his new car to his parents back home;

>> Sgt. Jeff Pugliese of the nearby Watertown Police Department (J.K. Simmons), leaving home to get coffee for himself and his wife.

“Patriots Day” also, and this is one of its strengths, spends quiet time with the two bombers, brothers Tamerlan (Themo Melikidze) and Dzhokhar Tsarnaev (Alex Wolff). The film is careful to be matter-of-fact here, not demonizing the brothers as drooling maniacs but presenting them in as straightforward a manner as possible.

Once the bomb goes off, “Patriots Day” offers a compelling re-creation of what went down at the marathon finish line, adroitly mixing archival news footage with multicamera handheld shots coordinated by cinematographer Tobias Schliessler to create sequences that show just enough carnage to allow us to understand what the experience was like.

After the explosion, the focus shifts to detailing what went on during the tense, focused 105 hours it took to identify and capture the brothers. Playing FBI Special Agent Richard DesLauriers, the man in charge, Kevin Bacon gives one of his best all-business performances.

One of “Patriots Day’s” most involving sequences takes us inside the massive Black Falcon warehouse evidence collection facility where the site of the bombing was meticulously re-created by investigators to help pinpoint exactly where the device went off.

“Patriots Day’s” most surprising element is the nighttime firefight in Watertown that ended things for the Tsarnaevs, an event that was not recorded and was apparently a lot more intense than reporting at the time indicated.

Though the film ends with a plea for the continued strength of the human spirit in the fight against evil, it is the tenseness of the actual situation (enhanced by an edgy score by Trent Reznor and Atticus Ross) that is the production’s lasting message. The heroism “Patriots Day” celebrates was unplanned and instinctive, and Berg and company are at their best when they honor that reality.