Freight railcar inspections are happening less often and are not as thorough as in years past due to staff cuts, time constraints and regulatory loopholes, a union official testified Friday during a federal hearing to examine the reasons behind a fiery train derailment in Ohio.

The National Transportation Safety Board said in its preliminary report that an overheating wheel bearing likely caused the Feb. 3 Norfolk Southern derailment that sent a plume of toxic black smoke into the sky near East Palestine, Ohio. Several tank cars were damaged in the crash, and officials decided that five of them containing vinyl chloride needed to be blown open to release the chemical and prevent an explosion.

It’s not clear whether an inspector would have been able to catch that the bearing was failing because it is sealed within the railcar’s axle. No inspector was even given a chance.

Jason Cox with the Transportation Communications Union testified Friday during the second day of the NTSB hearing that the railcar that caused the derailment wasn’t inspected by Norfolk Southern even though it passed through three railyards where qualified inspectors were working.

Cox said the lack of inspections reflects changes Norfolk Southern has made since 2019 to slash the ranks of car inspectors and other employees, and that the company increasingly uses a loophole in federal regulations to rely on train crews to complete inspections instead of experts trained to do that work. He said train crews look at just 12 points on a rail car instead of the 90 to 105 points a carman checks.

Furthermore, Cox said, carmen are pushed to inspect a car in just one minute instead of the roughly three minutes they had before the railroad started making operational changes over the past four years.

On Thursday, first responders and others testified about the difficulties they encountered in identifying the train’s cargo, and reviewed why officials decided to release and burn the toxic chemicals. On Friday, residents, local officials and others heard testimony about the wheel bearings, trackside detectors and tank cars.

After officials released and burned the vinyl chloride in the days following the derailment, roughly half the 5,000 East Palestine residents had to evacuate their homes. State and federal officials have said the air and water around town is safe, but residents continue to worry about possible long-term health effects from the derailment.

Norfolk Southern’s Hopewell and Mike Rush with the Association of American Railroads trade group that sets standards for the industry said railroads are taking the Ohio derailment seriously and making changes to prevent any future derailments, including adding hundreds more trackside detectors that are supposed to spot overheating bearings before they cause a crash.