A Florida high school was built on the grave sites of 145 coffins believed to be buried in a predominately black cemetery in Tampa, an underground radar survey has found.

School officials at C. Leon King High School in Hillsborough County, Florida, said they received a tip about a month ago that the school may have been built on the site of a historic cemetery. 

The school soon hired a team to use ground penetrating radar to map the area beneath the school. A report of their findings made public Wednesday said radars detected 145 coffins or voids left by decayed coffins buried 3 to 5 feet deep.

“The radar, by itself, cannot tell exactly what is under the surface. However, the pattern of the findings matches with historical records of a one-acre cemetery on the site,” school officials said in a news release.

The area has been fenced off to the public since the school received the tip.

An agricultural workshop building and lab facilities have been on the site since the late 1970s, the school said. School officials said they are now planning to remove that building.

The site of 250 to 268 graves, Ridgewood Cemetery was an “indigent cemetery with primarily African American burials,” school officials said in a statement, citing city and genealogical records.

Although only 145 burials were confirmed in the radar scan, the school said it’s possible the others were not detected for a variety of reasons, including that they are child burials or burials that occurred so long ago that they cannot be detected. Some of the burials may also be located beneath the agricultural workshop, the school said.

As many as 77 of the burials could be the grave sites of infants or small children, the school says.

According to the Tampa Bay Times, the city opened the cemetery in 1942. In 1957, the city sold a 40-acre plot of land, including the cemetery, to a private company, which later sold it to the school district two years later, the Times reported.

“Certainly, back in that day, profits were put over people, especially people who look like me,” said Hillsborough School Board chairwoman Tamara Shamburger, who is black, the newspaper reported.

Yvette Lewis, president of the Hillsborough Branch NAACP, told WFLA-TV that she was saddened by the news. 

“I am sick of this. This hurts. Deeply. That we can be thrown away and nobody tells our history. Nobody is telling these people’s history and these people’s story,” she told the station.

The school says they have turned the findings over to the county medical examiner and state archaeologist, who have 30 days to review the findings and determine whether they should keep possession of the land or turn it back over to the school district.

School district said that if they keep the land, they will work with community members to determine how best to move forward.

“We want to make sure that the folks that are buried at this site are honored,” Superintendent Jeff Eakins told WFLA-TV.

According to the Tampa Bay Times, this is the second forgotten cemetery believed to be the site of predominantly black graves found in the area in recent months. 

The other, Zion Cemetery, was found beneath a housing project. Five apartment buildings on the property are slated to be removed and converted into a memorial park, the newspaper reported.

Lewis said she wants something similar at the school, the Times reported.

“I don’t care what the dollar amount is,” she said, per the newspaper. “We have got to recognize the spirits and the souls, and the blood, sweat and tears that those people have contributed to this city.”

Follow USA TODAY’s Ryan Miller on Twitter @RyanW_Miller