TALLAHASSEE, Fla. (AP) — Sorrow reverberated across the country Sunday as Americans, including President Joe Biden, joined a Florida community in remembering the 17 lives lost three years ago in the Parkland school shooting massacre.

“In seconds, the lives of dozens of families, and the life of an American community, were changed forever,” Biden said in a statement released Sunday.

The president used the occasion to call on Congress to strengthen gun laws, including requiring background checks on all gun sales and banning assault weapons.

There was no time to wait, the president said. “We owe it to all those we’ve lost and to all those left behind to grieve to make a change. The time to act is now.”

Gov. Ron DeSantis ordered flags be lowered to half staff from sunrise to sunset across the state to honor those who perished when a former student of Marjory Stoneman Douglas opened fire on campus with an AR-15 rifle on Valentines Day in 2018.

When the gunfire ended, 14 students and three staff members were dead, and 17 others were wounded. The suspect, Nikolas Cruz, is still awaiting trial.

In his proclamation for a day of remembrance, DeSantis asked fellow Floridians to pause for a moment of silence at 3 p.m. Sunday.

“The Parkland community is resilient in the wake of tragedy, reminding us just how strong and united Floridians can be in the face of such devastating loss,” the governor said in his proclamation.

The Republican governor also noted some of the school safety measures enacted since the tragedy three years ago, including money to install panic alert systems at schools across the state and to strengthen programs meant to prevent violence before they occur.

The panic alert measure was dubbed “Alyssa’s Law,” in honor of 14-year-old Alyssa Alhadeff, one of the students killed three years ago.

But critics say the governor and Republican-controlled Legislature have done little to keep guns away from potentially bad actors and have opposed the ban of assault-style guns.

It remains to be seen what will be done on the federal level, despite Democratic control of the White House and both chambers of Congress.

“This Administration will not wait for the next mass shooting to heed that call. We will take action to end our epidemic of gun violence and make our schools and communities safer,” the president said in his statement Sunday.

In addition to background checks and an assault-weapons ban, Biden is calling on Congress to outlaw high-capacity magazines and make gun manufacturers liable for the role their products play in violence.

“For three years now, the Parkland families have spent birthdays and holidays without their loved ones,” Biden said.

“Today, as we mourn with the Parkland community, we mourn for all who have lost loved ones to gun violence,” he said.

“Over these three years, the Parkland families have taught all of us something profound,” the president continued. “Time and again, they have showed us how we can turn our grief into purpose – to march, organize, and build a strong, inclusive, and durable movement for change.”

“The world and the nation still reels from the 17 innocent lives cut short by senseless gun violence at Marjory Stoneman Douglas High School, but nowhere more than in our state of Florida. The passage of time has done little to heal the heartbreak we felt upon hearing the shocking news three years ago today, nor dulled our sense of outrage at the lack of consequential legislative action from lawmakers since that horrible morning — laws that would prevent another Parkland from ever happening again. As we continue to mourn this tragedy and keep the families of those lost in our hearts, we must also honor the fallen with real action. We must recommit ourselves to ending the epidemic of gun violence in our country by pushing our leaders to pass common-sense gun reforms that will allow us to build a safer America and a safer Florida. A nation and a state where parents do not have to fear sending their children to school, and communities are not scarred by the constant threat of gun violence.”

President Joe Biden