The fire that killed two firefighters on Linden Heights Avenue last year was ruled an accident, the Baltimore City Fire Department announced Friday, just shy of the one-year anniversary of the blaze.

The fire, which broke out in the 5200 block of Linden Heights Avenue in Northwest Baltimore on Oct. 19, 2023, had been under investigation by the Maryland Occupational Safety and Health Administration and the Bureau of Alcohol, Firearms and Tobacco.

MOSH concluded that there were no violations of workplace safety laws or regulations, and ATF determined the fire was accidental, though investigators could not determine the cause, fire officials said.

Fire investigators could not eliminate two separate hypotheses for the cause of the fire: A failure of the building’s electrical system or the improper disposal of smoking materials. The fire started in a rear addition to the home, investigators said.

“The loss of our colleagues in the Linden Heights fire is a profound tragedy that deeply affects our entire department and the community,” Baltimore City Fire Chief James Wallace said in a statement. “Our firefighters put their lives on the line every day, and it is heartbreaking when such sacrifice results in loss.

Firefighters called out “Mayday” minutes after arriving to the growing fire last year, which triggered a scramble among first responders and dispatchers.

Two men were killed: 31-year-old Rodney Pitts III and 26-year-old Dillon Rinaldo. Three others were injured.

Loved ones remembered Rinaldo, a captain, as larger than life. He had a booming voice and presence that could light up a room. He was hired by the city fire department in 2017, after a childhood where he was known as the “firehouse kid” in New Jersey.

Rinaldo initially survived the fire but succumbed to injuries while in the hospital.

Pitts was firefighter and EMT at Engine 29 who had just completed one year of service. His family remembered him as a loving father who worked multiple jobs to support his children.

He graduated from Digital Harbor High School in 2011 and was an avid fan of the Ravens and the Orioles.

Baltimore City fire officials said the department is committed to upholding “the highest standards of safety and operational excellence.”

“We will continue to review our practices and protocols to ensure the protection of our personnel and the communities we serve,” officials said in a statement.

The Baltimore Fire Department put new rules in place after the deaths of Rinaldo and Pitts.

The new regulations call for firefighters to have a comprehensive risk/reward analysis is completed by the Incident Commander and make sure the structure is sound for members to operate safely inside, as determined by the Incident Commander. And all fires at confirmed vacant buildings can only be extinguished from the outside unless there is an actual sighting of a person trapped inside.

Firefighters are required to stay outside of blazing buildings until certain conditions are in place and must make a significant knockdown of visible fire and have a complete 360-degree evaluation of the building, including a report from the roof, when possible.

This is a developing story.