PENSACOLA, Fla. - The Florida jail crippled by an apparent gas explosion was the subject of a five-year investigation that uncovered a facility so "grossly" understaffed that posts went unmanned and cells were seldom searched. Violence was pervasive and inmates were segregated by race.

Investigators are now trying to figure out whether the blast was an accident or something that could have been prevented. Inmates have told family members, the news media and their attorneys they smelled gas ahead of the explosion, but the county said they had no record of those concerns.

Still, questions were being raised about a jail with a documented record of troubles. The conditions at the Escambia County Jail were outlined in a Justice Department report last year and the facility was then treated like a hot potato among local officials.

In the midst of the turmoil - and during an unprecedented rainstorm last week - the basement was flooded with more than two feet of water and the jail was running on generator power.

Then, the blast hit. Two prisoners died, nearly 200 inmates and guards were injured, and the jail was all but destroyed in the explosion late Wednesday. In the confusion and chaos, 600 inmates rushed out of the building and authorities temporarily lost track of three inmates.

Bruce Miller, the elected public defender for the First Judicial District that includes Escambia County, said Friday that he has long been worried about conditions and understaffing at the jail and hoped the explosion provided another chance for review.

A prison guard union representative said the past problems and the explosion may not have anything to do with each another. He said officers train for fires and other emergencies every quarter. "Nobody went into the day thinking anything was going to happen. For them to have gotten those people out like they did, they followed their procedures to the button," said Alan Miller of the Northwest Florida chapter of the Police Benevolent Association.

"We're here to get to the bottom of this, but it's going to take some time," said Ashley Carr, spokeswoman for state fire marshal Jeff Atwater. "Was this a tragic accident, or was this the result of someone's action or inaction, and if so, who?"