The mass shooting that left 12 people dead at a midnight screening of “The Dark Knight Rises” in Colorado is already reverberating around the business and the nation as the latest deadly lone-gunman rampage spurs massive media coverage and forced the cancellation of the Warner’ picture’s premiere in Paris today.

Twelve moviegoers were shot dead and many more wounded at the midnight screening of “The Dark Knight Rises” in Aurora, Colo. early Friday morning. A gunman walked into a Century 16 theater in Aurora, about seven miles east of Denver, minutes after the 12:05 a.m. start of the latest “Batman” film.

Warner Bros. execs were reeling from the news Friday morning. Studio quickly canceled plans for the “TDKR” premiere in Paris today, which was due to be attended by director Christopher Nolan and key cast, but beyond that sources said there’s been no time to consider whether the tragedy will spur any changes to marketing campaign or have other fallout for the pic.

“Warner Bros. and the filmmakers are deeply saddened to learn about this shocking incident. We extend our sincere sympathies to the families and loved ones of the victims at this tragic time,” the studio said in a statement.

On Friday morning, U.S. TV news outlets mounted extensive coverage of the mass slayings. ABC and CBS were confirmed to broadcast their nightly news programs from Auroa on Friday as a horde of journos descend on the Denver suburb. “TDKR’s” association with the slayings is sure to be a PR nightmare for Warner Bros., which has so carefully tended its Batman franchise over the decades. By early Friday morning, ABC News was branding its coverage: “Tragedy in Colorado: The Batman Massacre.”

TV newsers were quick to point out that Aurora is less than twenty miles from Columbine High School in Littleton, Colo., where two students shot and killed thirteen people in 1999.

MPAA chief Chris Dodd expressed “the shock and sadness of everyone in the motion picture community at the news of this terrible event” in a statement issued Friday morning.

President Obama address the mass slaying with remarks delivered before a previously skedded speaking engagement in Fort Myers, Fla. on Friday.

“Michelle and I are shocked and saddened by the horrific and tragic shooting in Colorado. All Of us have the people of Aurora in our thoughts and prayers as they confront the loss of family, friends and neighbors, and we must stand together with them in the challenging hours and days to come. .. As we do when confronted by moments of darkness and challenge, we must now come together as one American family.”

The shootings are likely to prompt calls for tighter security in movie theaters. It is believed that the Aurora tragedy marks the deadliest shooting incident ever at a U.S. exhib.

In a statement from the National Assn. of Theater Owners, the org said, “On behalf of all the members and staff of NATO, our hearts and prayers go out to the victims of this despicable act and their families. We are grateful for the quick and effective response by police and emergency personnel. Guest safety is, and will continue to be a priority for theater owners. NATO members are working closely with local law enforcement agencies and reviewing security procedures.”

AMC Theaters issued a statement saying, “For the safety and security of our guests and associates, we are actively working with local law enforcement in communities throughout the nation and under the circumstances we are reaching out to all of our theatres to review our safety and security procedures.”

Latest details from the Aurora Police Department state twelve people have died with ten bodies still at the crime scene and at least two more dying at area hospitals. At least fifty people were shot, including the deceased with victims taken to at least six area hospitals according to BBC News. Reported victims being treated in area hospitals range in age from three months old to forty-five. Some of the bullets pierced the wall of the theater adjacent to the “TDKR” screening.

One man was arrested in the parking lot of the theater following the incident. Aurora Police Chief Dan Yates said there was no evidence of any additional shooters. The man, identified as 24-year-old James Holmes, was found in possession of a rifle and a hand-gun and wearing a bullet-proof vest and riot helmet.

“Witnesses tell us he released some sort of canister,” Yates said in a statement. “They heard hissing sounds and some gas emerged and then the gunman opened fire.”

Witness Paul Oterman told Sky News a man entered the theater through an emergency exit at the front right of the auditorium wearing a flack jacket and a gas mask.

“I thought it was a publicity stunt for a second there and then he threw tear gas over the crowd,” said Oterman. “As soon as he let go of it i could feel it in my eyes and I could tell something was about to go really wrong, and then he started firing shots into the crowd.”

An explosive device was also reported found in the theater.

Witnesses told the KUSA-TV, the NBC affiliate in Denver, that the gunman tossed two canisters to the ground, and once they exploded, spectators began ducking or running out of the theater, an escape made difficult by the blinding gas.

“He looked so calm when he did it,” the witness told KUSA.