By railroad standards, the freight train derailment Thursday in Pittsburgh’s Hazelwood section was barely a blip on the map compared to an accident involving tank cars carrying hazardous chemicals or flammable crude oil. “You can’t compare it,â€? said Glenn Cannon, an expert in emergency response matters who has formerly served as Pittsburgh’s public safety director, an assistant administrator in the federal Department of Homeland Security and director of the Pennsylvania Emergency Management Agency. “This was mundane. Trains derail all the time.â€? No one was injured when the empty freight train owned by Allegheny Valley Railroad and operated by Carload Express derailed about 10 a.m. near Second Avenue in Hazelwood. Thirteen hopper cars went off the rails and toppled over, some separating from their wheel sets. Five locomotives were pulling the train, according to Pittsburgh Chief of Operations Guy Costa. Nearby roads were blocked for about an hour. The Federal Railroad Administration is investigating the derailment, which occurred as the train was leaving the Glenwood Yard, which is leased by Allegheny Valley from CSX Transportation. The track involved is still considered a “yard trackâ€? and not a main line, said FRA spokesman Michael England. CSX, which operates freight rail traffic on the main line, was not affected. AVR declined to comment. The accident could have been much worse, said neighbors and experts. Jimmy Cohen, whose plumbing business has a warehouse just feet from the tracks farther down Irvine, said he rushed to the scene to make sure nothing happened to his property. “My building is six feet away from the tracks. … If that train had tipped the other way near it, it would’ve gone right into the building,â€? he said. Only a few other homes and businesses were in the immediate vicinity of the derailment, including Carnegie Mellon University’s robotics roundhouse. Much of the area is largely vacant, awaiting the planned Almono residential and commercial development site on the former LTV Steel plant or part of the Hazelwood Trail, a section of the popular Three Rivers Heritage Trail. That type of close proximity in a developed area, Cannon said, would make a chemical derailment much more dangerous. “(Hazardous material) derailments are extremely dangerous and difficult,â€? he said. “To occur in an urban area just makes it all that much more dangerous. A lot of times, you protect the exposure, and you evacuate and let the thing burn itself out if you can. That’s a problem. What happened today is not a problem.â€? Records released last fall by the state Emergency Management Agency showed that up to 75 trains a week passed through Western Pennsylvania on their way east to refineries. Each carried at least 1 million gallons of potentially flammable crude oil. Not all of it makes it safely to its destination. In February, a train carrying crude oil derailed in rural Mount Carbon, W.Va., sending fireballs into the air and burning for days. In 2014, rail cars hauling propane gas and Canadian crude oil derailed in Vandergrift, spilling thousands of gallons of crude oil. A CSX train with tanker cars derailed on a bridge over the Youghiogheny River in McKeesport, leaving some cars dangling over the trestle. Fortunately, no chemicals were spilled. The train in the derailment Thursday included box cars and tank cars, though the total number of cars in the long train was not available. Responding police officers and firefighters treated it as a possible hazard until determining the cars were empty. Mike Huss, Pittsburgh’s deputy director of public safety, said the city gets “commodity flowâ€? reports showing what kind of materials are being moved by rail and where, but he declined to specify those materials for safety and security reasons. Knowing the materials helps first responders plan for incidents, he said. “That’s not one of our main-line railroads. It’s generally low-speed, and not a lot of train activity,â€? Huss said. “It doesn’t get the volume or the types of material as the main line.â€? Matthew Santoni and Megan Guza are staff writers for Trib Total Media. Email Newsletters TribLIVE's Daily and Weekly email newsletters deliver the news you want and information you need, right to your inbox.