By John Miller, Amanda Musa, Rebekah Riess, David Goldman and Brynn Gingras, CNN

New York (CNN) — UnitedHealthcare CEO Brian Thompson was shot and killed in Midtown Manhattan Wednesday morning in a “brazen, targeted attack” as he walked toward the company’s annual investor conference, New York police said. The gunman remains on the loose.

Shortly before 7 a.m., a gunman, masked in the freezing temperatures, “was lying in wait” before opening fire on Thompson, according to NYPD commissioner Jessica Tisch.

“Many people passed the suspect, but he appeared to wait for his intended target,” she said. “I want to be clear: At this time, every indication is that this was a premeditated, preplanned, targeted attack.”

The gunman approached Thompson from behind and shot him at least once in the back and once in the right calf, Tisch said. Responding emergency workers took Thompson to Mount Sinai West in critical condition, where he was pronounced dead at 7:12 a.m.

“Investigative efforts of the New York City Police Department are well underway, and we will not rest until we identify and apprehend the shooter,” Tisch added.

The suspect fled — first on foot, then on an e-bike — and was last seen in Central Park early this morning, police said. Investigators are continuing to canvas the area.

Thompson, who was visiting from Minnesota, was shot with a weapon that appeared to be outfitted with a silencer, according to a law enforcement official. The motive for the shooting remains unclear, but Thompson’s wife Paulette told NBC News “there had been some threats” against her husband.

“There had been some threats,” she said in a phone call to NBC News. “Basically, I don’t know, a lack of coverage? I don’t know details. I just know that he said there were some people that had been threatening him,” she said.

Paulette Thompson declined to comment to CNN on the threats she described to NBC.

“We are shattered to hear about the senseless killing of our beloved Brian,” she told CNN Wednesday. “Brian was an incredibly loving, generous, talented man who truly lived life to the fullest and touched so many lives. Most importantly, Brian was an incredibly loving father to our two sons and will be greatly missed.”

The shooting happened at West 53rd Street and 6th Avenue in Midtown Manhattan, just blocks from Rockefeller Center where the annual Christmas tree lighting event will be held Wednesday night.

NYPD Crime Stoppers has announced a reward of up to $10,000 for information leading to the arrest and conviction of the person responsible.

The manager of a parking garage across the street from the hotel told CNN he was inside his office at the time of the shooting and did not hear gunshots.

Thompson was ‘truly extraordinary person,’ parent company CEO says

Thompson was named chief executive officer for UnitedHealthcare in April 2021. UnitedHealthcare is part of UnitedHealth Group, America’s largest insurance company and one of the country’s biggest companies, period: UnitedHealth Group is the fourth-largest company in America as ranked by revenue, according to the annual Fortune 500 list.

UnitedHealthcare’s parent company, UnitedHealth Group, abruptly ended its scheduled conference Wednesday morning, citing “a very serious medical situation with one of our team members.”

By late morning, flags were lowered to half-staff at United Healthcare’s headquarters in Minnetonka, Minnesota.

Later, UnitedHealth Group CEO Andrew Witty addressed the shooting in a minute-long video sent to employees. “There are no words to describe how so many of us are feeling right now,” he said in the video obtained by CNN. “Brian was a truly extraordinary person who touched the lives of countless people throughout our organization and far beyond. It’s a terrible tragedy and I know we are in shock and disbelief.

“We are deeply saddened and shocked at the passing of our dear friend and colleague Brian Thompson, the CEO of UnitedHealthcare,” a public statement from the companysaid. “Brian was a highly respected colleague and friend to all who worked with him. We are working closely with the New York Police Department and ask for your patience and understanding during this difficult time. Our hearts go out to Brian’s family and all who were close to him.”

Minnesota governor calls death a terrible loss

New York Gov. Kathy Hochul has directed state police to provide NYPD “with any necessary assistance with the investigation to ensure the safety of all New Yorkers.”

Minnesota Gov. and former vice presidential candidate, Tim Walz, called Thompson’s death “a terrible loss for the business and health care community in Minnesota.”

“This is a horrifying and shocking act of violence. My thoughts are with Brian Thompson’s family and loved ones and all those working at United Healthcare in Minnesota,” Senator Amy Klobuchar said in a post on X Wednesday morning.

“I’m horrified by the assassination of my constituent, Brian Thompson, this morning in NYC and have his family in my prayers,” Congressman Dean Phillips, of Minnesota’s 3rd District, wrote.

CNN’s John Miller, David Goldman and Brynn Gingras reported from New York. Amanda Musa and Rebekah Riess reported and wrote from Atlanta.