(CNN) -- Authorities trying to help a sick man and a child in a truck on a Florida highway also found a dead body in the vehicle Monday.

The incident started in the morning when a pest control truck pulled to the side of the road on I-95 in the West Palm Beach area.

Firefighters came to the scene and found a man and a boy suffering from some type of illness, said Chase Scott, a spokesman for West Palm Beach police.

Both were rushed to hospitals and were in serious condition, Scott said. Some of the firefighters on scene also became sick from fumes coming from the vehicle and had to be hospitalized.

Hazardous material teams were called in and while going through the truck authorities found a body inside a bag, Scott said.

The man and the boy had not been charged but authorities had searched the man's home, located in southwest Dade County, Scott said.

Scott did not provide much information on the body that was found in the truck.

The incident snarled traffic on heavily traveled I-95 for hours, CNN affiliate WPBF reported.

The substance that sickened people was a jug of an acid-based solution, the affiliate reported.