He said the four other children are injured by are expected to recover while the other adult woman is not "as severely injured", but remains in the hospital.
The other killed truck driver was identified as 49-year-old Douglas Bolkema of Albuquerque, New Mexico, WPBF reported.
Only the last driver, 61-year-old Mark Houghtaling, also of Gainesville, was physically spared.
Bryan Ross, affiliated with Avoyelles House of Mercy, said that the group, which included the pastor's wife, had set off from Marksville on Thursday morning.
"She is pretty banged up", Eric Descant is quoted as saying in the Facebook post.
Both the truck and auto went out of control and through the center divider, where Holland's truck plowed into the church van, driven by Amy Joffiron, 49, causing it to flip several times and eject some of the nine children on board.
The officer said the young victims were on a church passenger van from the state of Louisiana and the crash happened at 3:40 p.m. Thursday south of Gainesville in Florida, an hour of drive north of Walt Disney World, a popular theme park in Orlando.
Both vehicles traveled into the center median, slammed into the guardrail, and entered the southbound lanes of the Interstate.
Five of those killed were passengers in the church van. He says when the trucks collided they caught fire.
The highway patrol said preliminary information indicates that a tractor-trailer and a vehicle traveling northbound on I-75 collided and went through a guardrail, entering the southbound lanes.
At least eight other people, including a pregnant woman, were injured in the crash.
The investigation into the crash continues.
Flames engulfed the two 18-wheelers and spewed out onto the highway amid a diesel spill.
The church van was headed to Disney World in Florida.
Seven people were killed in a multi-vehicle crash that took place on Interstate 75 outside Gainesville on Thursday, according to the Florida Highway Patrol.
Six to eight people were transported to the hospital with injuries, authorities said Friday.
Emergency crews extinguished the fire and said they were treating the crash as a homicide investigation, but didn't say why.
Authorities are now attempting to notify next of kin of the deaths.
The aftermath closed part of the highway in both directions, causing massive delays.
Diesel fuel leaked and the mass erupted in a fireball.
According to the Florida Highway Patrol, a tractor trailer truck and a vehicle in the northbound lane collided and careened through the median into the southbound lane, hitting the United Pentecostal Church van and another tractor trailer truck. The fire occurred after almost 50 gallons of diesel fuel spilled onto the road.