A day after a gunman burst into a country music bar and opened fire, killing a dozen people in Thousand Oaks, California, the all-too-familiar executive order came from Gov. Brian Sandoval’s office.

It was time to lower the American and state flags again following another tragedy. The governor, as he had done before, turned to Twitter to make the announcement more widely known.

“I have ordered the flags to half-staff until sunset on November 10 as a mark of respect for and in remembrance of the victims in Thousand Oaks, California,” he tweeted earlier this month. “On behalf of all Nevadans, Lauralyn and I send our deepest sympathies to those affected.”

And so down came the stars and stripes, bowed as if crumpled in grief. Half-staff flags signal a nation or state in mourning — and, in the past few years, there has been no shortage of that. Las Vegas. Orlando. Sante Fe. Sutherland Springs. Parkland. Pittsburgh. And, now, Thousand Oaks. All rocked by mass shootings. All in various stages of recovery.

In the aftermath of each senseless shooting, half-staff flags stand as a symbol of sadness. But flags are lowered for other times of mourning, including the death of prominent state or national figures and days reserved for remembrance. Combine all the events that could trigger such a declaration, and it’s not uncommon to see the American flag flapping in the wind farther down the pole.

A Nevada Independent analysis of executive orders during Sandoval’s second term found that flags were flying at half-staff for 8 percent of 2015, 18 percent of 2016 and 7 percent of 2017. So far this year, flags have been half-staff 11 percent of the time.

The executive orders read like a solemn timeline, memorializing one tragic event after another. Take June and July of 2016, for instance. The Pulse nightclub shooting in Orlando brought flags to half-staff on June 15 and 16. Several weeks later, Old Glory came down again — this time in mourning for five police officers ambushed and killed in Dallas. Then a terrorist mowed down Bastille Day crowds in Nice, France, killing 86 people. American flags flew at half-staff for five days in mid-July. Back on American soil, a fourth tragedy — the slayings of three law enforcement officers in Baton Rouge, Louisiana — kept flags lowered through July 22 that year.

By the end of 2016, flags were at half-staff for 64 days — or roughly the equivalent of two months.

Nevada arguably mourned more the next year, when a gunman fired into the Route 91 Harvest music festival, killing 58 people in Las Vegas. Hours later, Sandoval had ordered flags to half-staff and they remained that way until sunset on Oct. 6, 2017.

Flags were lowered again on Oct. 1 this year to remember the victims on the one-year anniversary of the Las Vegas shooting.

U.S. Sen. John McCain, former First Lady Barbara Bush, astronaut John Glenn, Supreme Court Justice Antonin Scalia and Reverend Billy Graham are among the dignitaries whose deaths brought American flags to a lower-than-normal perch in recent years.

And for all the flag-lowering moments we can’t predict — and hope never occur — there are others that happen like clockwork each year.

There will be at least one more day of half-staff flags this year in Nevada: Pearl Harbor Remembrance Day on Dec. 7.