Disappointment abounded Tuesday in Forest Hills when a five-story Westinghouse atom smasher that had sat on the edge of town since 1937 was found knocked off its brick base and lying on its side.

The atom smasher on Ardmore Boulevard was the nation’s first Van de Graaf nuclear generator, and was recognized by the Young Preservationists Association of Pittsburgh as one of the city’s top 10 preservation opportunities in 2013.

In an email to the Pittsburgh Post-Gazette, the property’s developer said the atom smasher would eventually return to its former glory.

“The iconic Atom Smasher bulb survives!” wrote developer Gary Silversmith of Washington, D.C.

Mr. Silversmith purchased the property in 2012 with the hope of building apartments but said in January 2013 that he “would love to save the atom smasher.”

Mr. Silversmith said Tuesday that the atom smasher was knocked off the brick building where it had sat because the building was in “significant disrepair.” Vandals caused problems in the building and the cost to renovate the building for new use was “not economically feasible.”

He said a new base will be built and the atom smasher will receive a thorough paint job.

Although the atom smasher has not been active since 1958, many residents see it as representative of the atomic age and their own childhoods.

“I’m kind of traumatized,” said Michael Connors of Chalfant, which borders the atom smasher. “It’s like tearing down people’s heritage.”

“We’ve been robbed of our past,” said Gloria Blake of Forest Hills. “It’s like losing an old friend.”

Preservationists were upset, too.

Arthur Ziegler, the president of the Pittsburgh History & Landmarks Foundation, said “we certainly are unhappy with the loss.”

Marty O’Malley, the mayor of Forest Hills, said he was not aware of a permit for the demolition, but “that doesn’t mean there wasn’t one.” He expected to find out today.

Mr. Silversmith expressed hope that the Woodland Hills School District would “establish a STEM educational facility around the Atom Smasher bulb.”

Although such a plan was up for consideration in September 2013, Alan Johnson, superintendent of the district, said Tuesday that the $4 to $5 million cost is not feasible when the district already faces a shortfall. “We just don’t have that kind of money laying around.”

Despite Mr. Silversmith’s plans for the atom smasher, questions remain.

Ms. Blake watched several workmen attempt to roll the massive bulb onto its side Tuesday afternoon, ultimately giving up. “How in the world are they going to lift that thing up again?” she said.

And Barry Cassidy of Downingtown, Pa., who had been in charge of seeking grants for the restoration project, resigned last weekend when he came under the impression that the atom smasher would be destroyed. “I came here to save the atom smasher, not to knock [it] down,” he said.

Mr. Silversmith maintained that the atom smasher will be preserved and that Mr. Cassidy was misinformed about the plans for the project.

Whether or not the atom smasher will once again throw a shadow over Ms. Blake’s home, many people are upset.

“We feel like we’ve been deceived because all along we’ve been told that this thing would be preserved and now it’s lying on its side,” Ms. Blake said.

And Mr. Cassidy said he would have resigned even if he thought the atom smasher would be preserved.

“I think part of the historical character was the building it was in and I think the building could have been saved and the smasher could have been restored. It broke my heart.”

First Published: January 21, 2015, 1:37 p.m.