A crawfish boil explosion sent four people to the hospital in Krotz Springs, Louisiana.
CNN  — 

Four people were injured in Louisiana after an explosion at a crawfish boil, according to a volunteer fire department.

Two of the injured were firefighters with St. Landry Parish, according to Scott Fire Department. The firefighters were attending the crawfish boil in a Krotz Springs residential neighborhood on May 8 while off duty.

Jessie Bellard, St. Landry Parish president, told CNN affiliate KATC the explosion seemed to be an accident.

A propane tank was leaking inside of a shed, and a pot of crawfish was boiling right outside, Bellard told the affiliate. When the shed was opened, the propane ignited and caused the explosion.

The injured were airlifted to area hospitals. As of Thursday, the two firefighters were still in the hospital, along with one other victim, Bellard told CNN. The fourth victim has been released.