ISELTON, Calif. (KTXL) — One person was found dead inside a structure fire in Isleton on Wednesday morning, according to the Rio Vista Fire Department.

Crews arrived to the structure at around 1 a.m. with mutual aid provided by fire agencies from Isleton, Montezuma, Fairfield, Suisun City, Dixon and Vallejo.

Rescue efforts in the interior of the structure were made when the first crew arrived on scene. The building was already experiencing heavy fire conditions and structural compromise.

During the search and rescue effort a firefighter partially fell through the floor and was later determine to have no injuries by a medical team.

The trapped victim was located by fire crews, but was declared dead at the scene. The fire was knocked down just after 2 a.m. and the cause of the blaze is still under investigation.