Fire departments in America's biggest cities are overwhelmingly white. Why?

The New York City Fire Department has almost twice as many black firefighters as it did two years ago.

Sixteen percent of 2015 graduates were black, 23 percent were Latino, and 3 percent were Asian. By next summer, the department is set to have more black firefighters on its force than ever before, according to DNAInfo. And it’s no coincidence.

The increase in diversity comes after a lawsuit filed by the Vulcan Society, a black firefighters organization, compelled the city to change its hiring practices, change entry exams, increase recruiting goals, and create a chief diversity officer position. (Last year, all parties involved in the suit were also awarded $98 million.)

“The FDNY resisted change for decades,” said Gita Schwarz, a senior attorney at the Center for Constitutional Rights and an attorney in the case forced the FDNY to overhaul its hiring practices. Before the lawsuit, men of color in New York City’s fire department represented fewer than 6% of the force, according to PBS.

The number of black firefighters “is actually lower today than it was 25 years ago,” said public advocate Betsy Gotbaum in an affidavit quoted in the Vulcan lawsuit in 2001. “The firefighter force is the least diverse ethnically, racially, and by gender of all the uniformed services in the City.”

So, why is it important to have a diverse fire department?

“A fire department that is open to all New Yorkers is a stronger and more competitive fire department,” said Schwarz. “The FDNY serves an extraordinarily diverse New York City community, and firefighters who reflect that diversity can develop stronger partnerships with the neighborhoods they serve.”

The FDNY has worked to make substantive changes in community relations and recruitment. This year, the department has planned a first-ever open house night, inviting people to visit their neighborhood firehouses, FDNY representative Elisheva Zakheim told Fusion. It will also host a dozen block parties this summer “so that New Yorkers can learn more about the mission and opportunities,” he said.

Los Angeles and Chicago, the next two biggest American cities, have also been wrestling lately with increasing diversity in fire departments.

In Los Angeles, a hiring freeze has impeded progress. Last year, the first class of recruits in five years was heavily criticized for a lack of gender and racial diversity. According to the LA Times the class of 70 firefighter recruits was 60 percent white, 23 percent Latino, 11 percent Asian American and 6 percent black.

Los Angeles is 29 percent white, but the fire department is roughly half white, the Times reported. After calls to diversify the force, 2015’s numbers showed a more racially diverse batch of recruits, but not nearly enough to reflect the city’s residents of color.

Chicago, a city with a black population of 33 percent, and a Latino population 29 percent, has also come under scrutiny for its overwhelmingly white fire department.

In 2011, Chicago was ordered to hire 111 black firefighters by the next year after a civil-rights case found that the city used discriminatory hiring practices back in 1995. In 2012, the city inducted 86 officers who weren’t given the chance 17 years before.

Still, Chicago has work to do. According to DNAInfo, Chicago’s force is 65 percent white, 18 percent black and 15 percent Latino.

Collier Meyerson is a reporter at Fusion with a focus on race and politics. She lives in Brooklyn.