Firefighters and police officers gather at the scene of a house fire in the 300 block of River Edge Drive Tuesday, May 22, 2012, in unincorporated Lockport Township. No one was home at the time of the fire, and the house sustained extensive heat, smoke and fire damage. | Matthew Grotto~Sun-Times Media

Police and firefighters watch a Nicor crew at a townhouse fire in the 1700 block of Fieldstone Drive South Thursday, May 24, 2012, in Shorewood. | Matthew Grotto~Sun-Times Media

Firefighters work at the scene of a townhouse fire in the 1700 block of Fieldstone Drive South Thursday, May 24, 2012, in Shorewood. | Matthew Grotto~Sun-Times Media

Firefighters work at the scene of a townhouse fire in the 1700 block of Fieldstone Drive South Thursday, May 24, 2012, in Shorewood. | Matthew Grotto~Sun-Times Media

A view of melted siding at a townhouse fire in the 1700 block of Fieldstone Drive South Thursday, May 24, 2012, in Shorewood. | Matthew Grotto~Sun-Times Media

An investigator takes a picture at the scene of a townhouse fire in the 1700 block of Fieldstone Drive South Thursday, May 24, 2012, in Shorewood. | Matthew Grotto~Sun-Times Media

Firefighters and investigators gather at a townhouse fire in the 1700 block of Fieldstone Drive South Thursday, May 24, 2012, in Shorewood. | Matthew Grotto~Sun-Times Media

Firefighters and investigators gather at a townhouse fire in the 1700 block of Fieldstone Drive South Thursday, May 24, 2012, in Shorewood. | Matthew Grotto~Sun-Times Media

Firefighters and investigators gather at a townhouse fire in the 1700 block of Fieldstone Drive South Thursday, May 24, 2012, in Shorewood. | Matthew Grotto~Sun-Times Media

Firefighters gather at a townhouse fire in the 1700 block of Fieldstone Drive South Thursday, May 24, 2012, in Shorewood. | Matthew Grotto~Sun-Times Media

A firefighter drinks water during a response to a townhouse fire in the 1700 block of Fieldstone Drive South Thursday, May 24, 2012, in Shorewood. | Matthew Grotto~Sun-Times Media