Southbound I-25 is now back open following a deadly train derailment north of Pueblo last Sunday and northbound lanes are expected to open sometime Thursday. Officials say until cleanup is complete the speed limit will be 50 mph. BSNF is working to replace the bridge that collapsed during the derailment. They say there will be another scheduled closure in a few weeks. Federal investigators believe a broken rail may have caused the derailment and they’re looking into why warning systems failed to alert the crew.