Four firefighters suffer heat-related illness while battling fire at San Fernando church

Four firefighters required treatment from heat-related illness while battling a pesky fire at a church in San Fernando on Tuesday.

The blaze was first reported just before 1 p.m. at the First United Methodist Church of San Fernando, located in the 1500 block of W. Glenoaks Boulevard, according to the Los Angeles Fire Department.

It took around 100 firefighters more than two hours to fully extinguish the flames, which broke out int he attic of the one-story church.

"During the incident, four firefighters sought medical help from on-scene paramedics due to heat-related illness. Three of them rested and recovered on scene and then continue working, and one was transported to a local hospital for further evaluation and care," said a statement from the department.

The cause of the fire remains under investigation, but crews believe it may have been sparked by rooftop construction.

All people who were inside of the building when the fire started were able to safely evacuate.