BP's infamous Building 500 coming down in Naperville

More than two decades after BP Amoco started looking into why several workers at its Naperville campus developed brain tumors, the building that was ground zero for the probe is being demolished.

The razing of the infamous Building 500 along I-88 began in December. The project is scheduled to be completed by early this summer.

"They already have removed all the windows, and the interior has been gutted," BP Amoco spokesman Scott Dean said Wednesday. "Now they are doing the exterior work."

Dean said the 243,000-square-foot building is being torn down "strictly for business reasons."

The 503 wing of the building was closed in the mid-1990s while researchers looked for what caused a cluster of BP Amoco employees to develop brain tumors, including six who died of glioma after working in that wing.

Study results announced in August 1999 revealed the glioma cases were possibly work-related. But Dean said, "It didn't find a conclusive link to explain why the six people were stricken with brain cancer."

The study also didn't find any connection between the workplace and the other brain tumors and various illnesses reported by employees.

In fact, Dean said, it was determined that the overall work force at the research campus has a substantially lower death rate due to all causes, including cancer, than the general population.

"So the population at the facility is actually healthier than the population in general in Illinois," he said.

The shuttered wing never reopened after the study because BP Amoco had no need to use the space.

Dean said the rest of the building became expendable after the company sold off a large part of its chemical business in 2005. The structure, which has a mix of offices and laboratories, has been "essentially vacant" since July 2009, he said.

As the first building constructed on the Naperville campus, Building 500 is more than 40 years old. Dean said "significant investment" would have been needed to upgrade it to meet existing building standards.

"The Naperville campus covers 150 acres and has several buildings," Dean said. "We've updated many of them through the years. But in this case, this building was just too old and required too much work. It didn't really fit our needs anymore."

Even letting the building stand empty had a price tag.

"We still had to provide ventilation and temperature control," Dean said. "That was a cost that we were incurring without having anybody using the building."

Once the demolition is complete, Dean said there are no plans to construct a new building at the site.