Just two days after Lareece Williams Jr. took the fatal fall from his bedroom window at Linden Plaza in East New York, the toddler’s grieving parents filed suit in Brooklyn Supreme Court against the building’s owner alleging that it is responsible for the child’s tragic death.

By city law, landlords are required to install bars on the windows of buildings where there are three or more apartments and children who are 10 years old or younger are residing there — even on the first floor.

Not only did the window for Lareece’s bedroom lack bars but it also failed to close all the way, said Donte Mills, a lawyer for the Williams family.

“The action they were required to provide, they failed to provide,” Mills said.

Mills said the family contacted their building manager at least 10 times over the last year and a half about Lareece’s window, including two written formal notices and multiple calls and visits to the rental office in their building.

Just after Lareece’s fall, the city’s Health Department investigated the lack of bars at the Williams’ apartment — and the day after Lareece’s death, bars were installed on his bedroom window.

“It makes it worse to show that all it takes is one day to fix this repair,” Mills said.

Linden Plaza Housing Co., which is named in the lawsuit, could not be reached for comment. A message left with RY Management, which manages the property, was not returned.

In an interview with The Post, Lareece Williams, the deceased boy’s father, recounted the heartbreaking story of his son’s last moments.

He said his two sons were napping in the bedroom at around 11 a.m. on Monday when he heard people screaming from downstairs.

Williams said he ran to his sons’ room and saw only their youngest. He rushed downstairs, where he saw a crowd standing around and saw Lareece on the ground “fighting to live.”

“When I came downstairs he was still breathing, he was still fighting for his life,” the father said. “And I had to lose him like this.”