Investigators report on the Florida I-4 fog/smoke incident

fog-smokeInvestigators have released a report on the Florida January 8 incident that we reported on in which smoke from an escaped prescribed fire may have mixed with fog causing poor visibility on Interstate 4 resulting in five fatalities in vehicle crashes. The report issued by the Florida Department of Agriculture and Consumer Services says:

“…an unpredictable change in weather caused the prescribed burn to burn erratically which resulted in spot fires.”

Tampa Bay Online has more details:

“TALLAHASSEE – A state investigation has cleared wildlife officials who last month lost control of a prescribed burn that may have contributed to a 70-vehicle pileup on Interstate 4 in Polk County.

The investigation by the Florida Department of Agriculture and Consumer Services concluded changing weather conditions Jan. 8 caused the 10-acre planned burn to jump firelines and spread to 400 acres. The National Weather Service said smoke from the fire could have combined with fog the next morning to cut visibility on the highway to nearly zero.

Five people died in the predawn pileup and resulting fires, prompting questions about how the fire got out of control and whether the state should have held a controlled burn in the dry season less than a mile from the interstate.

The Florida Highway Patrol is conducting a homicide investigation that also will look at whether smoke from the wildfire played a part in the wrecks.

The report by the Agriculture Department’s law enforcement division states those in charge of the fire followed correct procedures but that an “unpredictable change in weather caused the prescribed burn to burn erratically which resulted in spot fires.”

“There does not appear to be any evidence of criminal violations or gross negligence” by those involved in the burn, investigators concluded in their report.

Fish and Wildlife Conservation Commission employees conducting the burn reported that the humidity had dropped sharply about an hour after the fire was set at 10 a.m. and winds picked up, spreading the fire outside the protective earthen barriers.

The National Weather Service confirms there was a drop in humidity at the fire site, but meteorologists said that could have been caused by the fire. As warm air from a fire rises, it forces drier air downward. Drier air aids the spread of fire, especially when rainfall has been sparse for a long period.

Daniel Noah, warning coordination meteorologist with the National Weather Service, said the agency has no way of knowing whether wind speeds around the fire picked up or wind directions changed. However, Noah did not rule out that possibility.”

A preliminary report issued by the Florida Highway Patrol does not even mention the prescribed fire.