Warren officials are preparing to spend $3 million on new fire engines because four rigs have been pulled out of service after failing inspections. Eliminating the four vehicles from the Fire Department’s front-line fleet has led to the potential for one-day “brown outs” – or temporary closures – of fire stations, and caused city officials to borrow a fire truck from neighboring Sterling Heights to prevent any station from shutting down. The four Warren fire engines were abruptly pulled out of service a few months ago after metallurgical tests showed the thickness of frame rails that support a lot of weight weren’t sufficient to meet emergency standards and could break, potentially causing an accident while a fire crew rushes to a fire. The initial test was conducted by the manufacturer of the vehicles, two of which were 2001 models and one each from 2002 and 2006. Officials ordered a second round of independent tests which verified the early conclusions.