PAULSBORO, N.J. (AP) — Conrail crews had reports of signal problems at a New Jersey railroad bridge weeks before a train derailment Friday, and were studying the problem the day before the crash and resulting chemical leak, federal investigators said Sunday.

Seventy people went to a hospital following the derailment. More than 100 people are expected to remain out of their homes this week while crews try to remove the hazardous material, vinyl chloride, from a ruptured tanker.