The two trucks caught fire, and both of their drivers were killed. Sister Karen Descant, the pastor's wife, and two other adult ladies were on board the van.
The children were members of the Avoyelles House of Mercy in Marksville, Louisiana, according to the Gainesville Sun.
"She is pretty banged up", Eric Descant is quoted as saying in the Facebook post. All northbound lanes of I-75 reopened at 8 p.m. Thursday.
The Highway Patrol said two vehicles traveling north - a tractor-trailer and a auto - smashed into each other and then burst through a metal guardrail, slamming into another semitrailer and the southbound van carrying the children.
At least seven people are dead after the devastating crash that involved two big lorries and two passenger vehicles.
"It is a heartbreaking event", Lt. Patrick Riordan said Friday.
Riordan says next of kin notifications are still underway. Only one southbound lane is now open on the road, but Florida Department of Transportation spokesman Troy Roberts said the agency hopes to have an additional lane open shortly.
Authorities will continue investigating how the crash unfolded, and part of that investigation will look into the guardrail that failed to stop the initial big rig and sedan from crossing into the neighbouring lane.
A semi-truck that was traveling north had struck a vehicle and crossed over with it into the southbound lanes - slamming into the van and another semi.
The highway patrol has scheduled a 10 a.m. news conference to discuss the investigation into the crash. Diesel fuel leaked, and the mass erupted into a fireball, the Highway Patrol said.
"Our homicide investigators - they do this on a daily basis".
"You have a awful accident with kids going to Disney to enjoy themselves and this happens", Lemoine said.
Seven people were killed - including five children who were in a van bound for Walt Disney World - in a fiery four-vehicle crash on Interstate 75 near Gainesville Thursday afternoon, the Florida Highway Patrol said.
Authorities are now attempting to notify next of kin of the deaths.
Authorities extinguished the fire, but the aftermath caused a portion of the motorway to be closed in both directions, causing massive delays.
Flames engulf vehicles after a fiery crash along Interstate 75 about a mile south of Alachua, near Gainesville. Fire officials say that 50 gallons of diesel fuel spilled as a result of the crash.
The fire has been extinguished.
"The other lady is not as severely injured, but is still in the hospital", they wrote on Facebook. The Gainesville Sun reports some of the injuries were critical. A law enforcement helicopter was sent aloft to try to see if any of the injured were in the woods along the crash scene.