The company that runs the Discovery Channel and multiple other networks will leave its headquarters in Silver Spring, Maryland, the company told employees in an email Tuesday.

Discovery Communications will move its global headquarters to New York City, CEO David Zaslav said.

"We have ... made the difficult decision to reduce our footprint in Maryland over time, with the ultimate closure and sale of our One Discovery Place headquarters building in Silver Spring, expected in 2019," he wrote.

Chief Corporate Operating Officer David Leavy spoke with News4's Chris Gordon about the decision.

"We are a Silver Spring company -- no doubt. We also have to do what's in the best interest of our company and our shareholders, so that leads us to move to New York," he said.

The decision affects 1,300 employees. Some told News4 they were waiting to see if they would be offered a job to stay with the company and relocate, or if they would have to find another job.

The company told employees they have "not yet embarked on all the planning to determine which functions will be moved to which location."

Officials in Montgomery County and the state of Maryland tried to convince Discovery to stay, Montgomery County Executive Ike Leggett said.

"The county and state made a substantial proposal designed to accommodate Discovery’s challenges," he said in a statement. "Together, we were ready to provide considerable incentives to retain their presence in the county."

He said the move will have a "negative impact" on the county.

"It will be a negative impact on our tax base because you lose that number of employees. You can't replace all of those employees overnight," he said.

Discovery opened its headquarters off Georgia Avenue at Colesville Road in 2003, sparking economic development in downtown Silver Spring.

Resident Allan Griffith III questioned what will happen after Discovery leaves.

"I remember how we languished with no development and a lot of boarded-up buildings," he said. Development was brought here by the arrival of Discovery, and I just wonder, will we see some sort of downturn with them leaving?"

Worker Toby Goss said he expected the departure of Discovery to hurt local restaurants and bars.

Discovery Communications announced in July they would buy Scripps Networks for nearly $12 billion. The company now runs TV channels including Animal Planet, TLC, Investigation Discovery and OWN.

Discovery said decisions on individual job status and relocation will be made after the closure of the Scripps acquisition. The company plans to make Scripps' Knoxville, Tennessee, campus its national operational headquarters.

Huge murals advertising Shark Week were installed on the building for years. For a number of years, a shark named Chompie adorned the building, with fins and its head protruding from the sides.

A man held three people hostage in the building in September 2010 and then was killed by police. The hourslong standoff changed the lives of the hostages, forced the evacuation of a daycare center in the building and disrupted traffic. The armed man had a history of environmental extremism targeting the Discovery Channel.

Upon learning of the situation, NBC News producers called the building. A producer spoke with the man for about 10 minutes until he apparently ended the call. Meanwhile, other NBC News staff informed authorities.