Five adults were transported to the hospital, including one who jumped from a third-story balcony, after an apartment building fire on Christmas morning in Bellevue.

Bellevue firefighters were dispatched at 4:27 a.m. on Monday to reports of a fire at a Factoria apartment building in the 12800 block of SE 40th Court, according to the Bellevue Police Department.

Engine Co. 4 was the first to arrive to find the front stairwell of the building engulfed in flames, which blocked all occupant’s egress.

Residents from six units required assistance from firefighters to exit the building. Many were rescued with ground ladders, but one resident was injured as a result of jumping from a third-story balcony prior to the fire department’s arrival, police said.

Five adults were treated at the scene and transported to a local hospital. The Red Cross provided resources and housing to those displaced by the fire.

At approximately 4 p.m., Bellevue fire investigators wrapped up their near eight-hour investigation into the fire’s cause and origin. They determined the fire started on the exterior of the building and burned its way to the inside of the structure. However, investigators could not determine the cause of the fire and have closed the investigation.

In all, 49 firefighters responded to the fire with two mutual aid units from Mercer Island. Tri-Med ambulance service provided two ambulances to assist with transporting patients to the hospital.