Haitians paused Sunday to remember the tens of thousands of people who died in a catastrophic earthquake four years ago, holding somber, low-key commemorations on a national day of reflection.

North of Port-au-Prince, the capital, President Michel Martelly and first lady Sophia Martelly placed a bouquet of white flowers at a burial ground that is being turned into an official memorial for those killed.

The pair observed a minute of silence while facing a plaque placed at a large piece of rubble, with the inscription: “Jan. 12, 2010. We will never forget you.”

Martelly said much has been accomplished since the disaster.

“Four years later, I think we have moved forward tremendously,” Martelly said in an interview. “Of course, a lot remains to be done.”

The 7.0-magnitude earthquake struck outside Port-au-Prince, and thousands of buildings toppled in the capital and surrounding cities. Officials said more than 300,000 died, but no one knows for certain how many people lost their lives.

An estimated 1.5 million people were left living in gloomy tent camps that became symbols of the devastation and desperation heaped upon an already impoverished nation. The number of displaced people has since fallen to 146,000, with the decline attributed to a combination of voluntary departures, rental subsidies and violent evictions.

The day began like any other Sunday in the capital, with churchgoers wending their way through streets noticeably clear of the rubble that clogged them long after the quake.

Martelly’s government declared a day of remembrance and reflection. Radio and television stations played somber programs and music.

“We need this, we need to remember our family members and friends who died,” Peterson Lebours said as he visited a memorial at the national cemetery. The 35-year-old teacher lost a cousin, and several friends and co-workers.

While many Haitians were remembering loved ones lost in the quake, activists used the occasion to criticize the reconstruction effort and nongovernmental groups promoted their work.

Former president Bill Clinton, a onetime U.N. special envoy to Haiti, sought to cast the day in a positive light in a statement on his foundation’s Web site: “As we remember this solemn anniversary, we also recognize that Haiti has the opportunity for a bright and prosperous future — one that its people and children deeply deserve.”

— Associated Press