An overnight passenger train derailed early Sunday in northern India, killing at least 115 people. Daljeet Chaudhary, a director general of police, believes the death toll will continue to rise because some of the most devastated coaches that derailed have not become accessible yet. An estimated 150 people were injured. The cause of the derailment was not immediately clear. The impact of the derailment was so strong that one of the coaches landed on top of another, crushing the one below. Accidents are relatively common on India's sprawling rail network, which is the world's third largest but lacks modern signaling and communication systems. Most accidents are blamed on poor maintenance and human error.