An explosion at an industrial complex in South Jersey has left four people critically injured and a fifth person working at an adjacent business. The explosion occurred at 2:36 p.m. at Savita Naturals, a company that processes cocoa butter for the chocolate industry. A large amount of propane is stored on the property, but it is unclear what caused the explosion. At least a dozen state, county and local agencies have responded to the blast, which caused extensive damage to the building and a neighboring building. The blast could be heard for miles, including in Delaware and Harrison Township, some 10 miles away.