Culture is not a press release. Culture is not a statement or a Twitter post. Culture runs deep. Culture is a shared narrative that lifts spirits and inspires people to do what is in the best interest of the customer. Above all, a culture of service starts at the top with leaders who consistently communicate the narrative and back it up with their words and actions.

The United Airlines fiasco is a PR disaster. It also offers a valuable lesson in how cultures are built, sustained and how fragile they are. Culture must be nurtured each and every day.

The video of security officers forcibly removing Dr. David Dao off an overbooked United Express flight has sparked outrage across the world. The first statement from United CEO Oscar Munoz failed to quell the anger when he used the word ‘re-accommodate’ in his apology. The second statement—in an email to employees—appeared to blame the passenger, which only exacerbated the firestorm. In the third statement Munoz seemed to validate the concerns of the public when he said the event was “horrific.” Today he said, “This will never happen again…that’s my promise.”

One major United investor told the Wall Street Journal that the company “took too long” to make an “unequivocal apology.” As a communication advisor who has been in the room with CEOs when a major crisis occurs, I can make an educated opinion on why it took so long. I can also suggest what United must do to change its culture and regain the public trust.

United lacks a cohesive narrative, a commitment to service that is so engrained in the company culture that every employee bases his or her decisions on making customers happy. The lack of narrative is common among many companies, which makes the ones who stand out even more exceptional.

For example, when I interviewed Richard Branson about customer service on Virgin Atlantic and Virgin Airlines, I saw a leader who walked the talk, literally. I spent the better part of a day with him as he visited hubs. I overheard him on the phone congratulating a crew in another city for going above and beyond expectations to help a customer. I saw him post examples of excellent customer service on his personal blog. Branson brought every conversation back to the brands’ core mission: elevating the customer experience.

While speaking to Virgin employees I heard the word ‘empowered’ more than a few times. At brands that are customer service champions, empowerment is the key to doing what’s in the best interest of the customer. According to a travel blog, Ask The Pilot, a lack of empowerment may have been at the root of the United Express fiasco.

When I hear more than one employee at a brand use the word “empower,” I know that the culture runs deep. One notable example is when I visited Zappos at its headquarters in Nevada. I brought a videocamera along, hoping to get some interviews I could post online. I was stunned when CEO Tony Hsieh said, “Walk around and talk to anyone you want.”

“Is there a PR person who will be with me?” I asked.

“No. We share everything. Go for it.”

I recall walking around in disbelief. This couldn’t be happening, I thought. I can talk to anyone, about anything? The commitment to service was so engrained in the company culture, the CEO didn’t mind who I spoke to. Why should he? The employees were empowered to do what is the right thing for the customer. That’s ultimate trust.

For a book on storytelling in business, I studied the culture at Southwest Airlines, speaking to senior leaders and long-time employees. To a person they trace the culture back to Southwest founder Herb Kelleher. Many businesses have tried to figure out the secret to Southwest’s success. Kelleher said the secret was so simple, many people didn’t believe it. Kelleher says the key to great service comes down to this:

“Treat your people well and they’ll treat you well.”

According to Kelleher, “Competitors can buy tangible assets, but they can’t buy culture.” Kelleher kept culture top of mind by talking about it constantly. He told stories about culture. Today, storytelling continues to be a major component of Southwest’s success as a customer service leader. For example, employees are expected to know the company’s purpose by heart:

“We exist to connect people to what’s important in their lives through friendly, reliable, and low-cost air travel.”

To make sure each and every employee internalizes the mission, CEO Gary Kelly gives a “shout out” — public praise — to employees who have demonstrated great customer service. Each month the Southwest Spirit magazine features the story of an employee who has gone above and beyond. Southwest highlights positive behaviors through a variety of recognition programs and awards. Finally, internal corporate videos are filled with real examples and stories to help employees visualize what each step of the purpose looks and feels like. Kelly likes to say they have a “healthy obsession” with improving the customer experience.

Culture is a narrative that starts at the top with leaders who share and reinforce the brand story every hour of every day. When employees have internalized the story of service, they begin to ask questions that may avert a crisis and build a brand employees are proud to work for and passengers are happy to support.

Read article on Forbes.com