The first traffic signals in the U.S. were installed in 1912 and featured two lights: Green for “go” and “red” for stop.

It wasn’t until about a decade later that a third light — yellow — was added to warn drivers that the light was about to change, a modification caused, no doubt, by bad experiences.

Our understanding is often informed by bad experiences on a large variety of subjects.

Two news stories this week — one today by The Dispatch, the other by Mississippi Today — remind us that economic development comes with a potential cost that should not be ignored simply in the interest of progress.

The Dispatch story concerned the joint city/county sale of the old Maxxim Medical Building to an ammunition company planning to expand its operations. The arrival of Apex Ammunition, which manufactures shotgun shells, reminds long-time residents of another local company whose handling of explosives ended in a tragedy. Early in the morning of June 12, 1990, an explosion ripped apart a fireworks plant on Concord Road, a blast that killed two people. The aftershock of the explosion could be felt as far away as Starkville.

In the other news story, using data from the Environmental Protection Agency, Mississippi Today reported on the Mississippi industries with the highest volume of pollution over the last five years. Of the top 50 polluters, five (10 percent) were located in our area.

It should be noted that just because an industry produces toxic releases doesn’t mean the emissions are at a level harmful to people. But it does emphasize that these emissions should be carefully monitored and mitigated as much as reasonably possible.

The greatest, most enduring local environmental tragedy is the old Kerr-McGee plant in Columbus, which for years leaked deadly levels of creosote into the soil and groundwater, sickening and killing workers and nearby residents for decades. It is now an EPA Superfund site, and it will be decades more before that property is entirely safe.

Those local examples underline the fact that asking questions about the environmental impacts of economic development deals shouldn’t be something we shy away from.

Citizens have every right to ask how potential industries may affect the environment and public health. Once bitten, twice shy, as the saying goes.

Demanding answers to those questions is a part of our due diligence as citizens.

Yet in some circles, asking these questions is viewed as being “anti-development” or may risk “killing the deal.”

It’s entirely possible to be pro-development yet still want reassurance on the long term effects of a project.

If simply asking the questions about public safety risks killing a deal, there are most likely legitimate reasons for concern.

With regards to the Apex Ammunition deal, we are encouraged that elected leaders asked questions about safety and that the company itself has been transparent with its plans.

There are two interpretations of what a yellow light signifies. One is “prepare to stop.” The other is “proceed with caution.”

Asking those questions — and the answers we get in return — informs us of which interpretation of the “yellow light” is best when evaluating new development.

The Dispatch Editorial Board is made up of publisher Peter Imes, columnist Slim Smith, managing editor Zack Plair and senior newsroom staff.