Only days before the third anniversary of the worst attack on gay people in the U.S., members of central Florida's congressional delegation said Monday they were introducing legislation that would designate as a national memorial the gay nightclub where 49 people were massacred by a supporter of the Islamic State.

U.S. Reps. Darren Soto and Stephanie Murphy, both Democrats, said at a ceremony outside the former nightclub that the designation will preserve and protect Pulse for future generations and give it the federal recognition it deserves. It will be three years on Wednesday that gunman Omar Mateen opened fire at the Orlando gay nightclub on Latin night. Mateen, who had pledged allegiance to the Islamic State, was killed in a shootout with police after a three-hour standoff inside Pulse.

At the time, it was the deadliest mass shooting in modern U.S. history. However, the mass shooting in 2017 along the Las Vegas Strip became the deadliest when 58 people were killed.

Pulse owner Barbara Poma has established a nonprofit to open a memorial and museum at the site. About $14 million has been raised for the $50 million project. Six design firms have been selected as finalists and the winner will be chosen in the fall. The permanent memorial and museum are scheduled to open in 2022.

Soto said the national memorial designation would allow the Pulse site to become part of the national park system while still allowing for the nonprofit to maintain control over it. Also backing the bill is U.S. Rep. Val Demings, D-Fla.

"This is an important step in preserving an LGBT historic landmark at a time when many of these sites are being destroyed," Soto said.

After the ceremony, several of the participants joined other activists at the local Supervisor of Elections office to present 103,000 petitions supporting a constitutional amendment on the 2020 ballot to ban the sale of assault weapons in Florida.

A petition must be signed by 766, 200 voters in at least 14 congressional districts to appear on an election ballot. Once 10 percent of that threshold is met, it can be sent to the Florida Supreme Court for review. Organizers from the Ban Assault Weapons Now coalition said that important threshold was met Monday. The coalition is made up of survivors and family members of victims of the Pulse shooting and the massacre at the Marjory Stoneman Douglas High School massacre in Parkland, Florida.

The ceremony at Pulse was interrupted briefly by the mother of Christopher "Drew" Leinonen, who was killed at the nightclub. Christine Leinonen began shouting at Poma when she came to the speaker's podium. Two police officers escorted her out of the ceremony, and they were followed by two state lawmakers and a city commissioner who talked to Leinonen for several minutes while the ceremony continued.

Afterward, Leinonen blamed Poma for inadequate security at the nightclub. Authorities say an extra-duty police officer working at the nightclub fired at Mateen from two locations outside Pulse, but didn't pursue him inside. Last year, some survivors and victims' relatives, including Leinonen, filed a federal lawsuit, claiming the city and police didn't do enough to try to stop the shooter. The lawsuit was dismissed in November, but the survivors and families are appealing.

Leinonen and other families also have sued Poma and her husband for negligence and wrongful death in state court and that lawsuit is pending.

"My son's blood is on her hands, and she's walking around like she's the hero," said Leinonen, who spoke at the Democratic National Convention in 2016. "This is Orlando. This is where everyone wants to be in a fairy tale. Well, guess what? My son wasn't in a fairy tale. My son was in a real-life horror movie."

When asked later about what Leinonen had said, Poma said, "Christine is a grieving mom. Everyone does it differently, and this is a rough week for every mother, every survivor and every first responder."

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