WASHINGTON -- The young daughters of Officer Stephen J. Mayhle covered their ears at the jarring noise made by the stone engravers while the rest of the family members and former colleagues of the three Pittsburgh police officers killed in the line of duty last year looked on.

Within a few minutes, the work of the two engravers was finished, and the names of Officers Mayhle, Eric G. Kelly and Paul J. Sciullo II were permanently carved into a national monument to fallen officers. Then they approached with paper and pencil to make rubbings of their loved ones' names to save.

The three officers who died in Stanton Heights on the morning of April 4, 2009, were officially etched into the National Law Enforcement Officers Memorial in Washington's Judiciary Square on Tuesday. The memorial bears the names of 18,983 peace officers who have died in the line of duty since 1792, including 65 from the Pittsburgh Police Bureau.

The trio was among 116 law enforcement officers who died nationwide last year, a number that has fallen steadily in recent years. Four other jurisdictions -- Oakland, Calif.; Okaloosa County, Fla.; Seminole County, Okla.; and Lakewood, Wash. -- suffered multiple officer deaths in a single incident last year.

Pittsburgh police Deputy Chief Paul Donaldson said the way the officers died, assisting each other on a domestic disturbance call, exemplified the bond all officers have to help each other "no matter the danger."

"It is this bond that provides us our strength and our very stability and it also is a measure of our loyalty to each other," Chief Donaldson said. "This bond, this commitment was evident on that morning for these officers truly served together and they fell together."

Chief Donaldson made his own rubbings of each of the three officer's names, offering a solemn salute after each one.

Craig Floyd, the chairman of the National Law Enforcement Officers Memorial Fund, hosted the event.

"I hope you leave today with a little bit of healing knowing your loved one is honored here on a national monument," Mr. Floyd said. "May these fallen American heroes rest in peace, and may they never be forgotten."

Looking for more from the Post-Gazette? Join PG+, our members-only web site. You'll get exclusive sports content, opinion, financial information, discounts from retailers and restaurants, and more. Our introduction to PG+ gives you all the details.