sentences:  On April 1, 2019, part of the bridge on I-75 southbound over the ramp from I-24 westbound to I-75 northbound at the split in Chattanooga collapsed, injuring one person and blocking traffic for hours.The bridge, built in 1959, is one of the oldest on I-75 in Tennessee, and the interchange is the site of frequent accidents.TDOT's chief engineer said that the collapse was most likely caused by weakening of the bridge's rail that occurred when an illegally oversized load hit the bridge.