CNN  — 

A Louisiana congregation was in mourning after five children riding in a church van bound for Disney World were killed in a fiery Florida crash.

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.

The other two killed in Thursday afternoon’s collision were men driving semi-trucks, Florida Highway Patrol Lt. Patrick Riordan told reporters at a news conference.

The crash happened near Gainesville, according to authorities.

The highway patrol said preliminary information indicates that a tractor-trailer and a car traveling northbound on I-75 collided and went through a guardrail, entering the southbound lanes. The truck struck the large passenger van and another semi-truck. A fifth vehicle struck some of the occupants or debris on the roadway, Lt. Patrick Riordan said.

Three girls and two boys in the van died. The condition of the pastor’s wife was unknown.

“It’s just a tragedy,” Ross told CNN.

A photo posted by Alachua County Fire Rescue showed a tractor-trailer in flames with a vehicle under it.

Patients transported from the scene have serious and critical injuries, authorities said.

A homicide investigation is underway, Riordan told reporters.

The FHP will issue a detailed statement on the accident after the families of the victims have been notified.

Clarification: This story has been updated to fix the spelling of Disney World.

CNN’s Steve Almasy contributed to this report.