Baltimore County authorities released dramatic new details about the Hillendale apartment fire Wednesday night that killed a Lutherville volunteer fireman, the first firefighter to die while actively battling a blaze since 1984.

The fire, which began in a basement kitchen, quickly spread through the three-story building in the Towson Crossing apartment complex on Dowling Circle. Firefighters arrived shortly after the 6:15 p.m. 911 call. The blaze quickly escalated to a total of four alarms.

Mark Falkenhan arrived with the Lutherville Volunteer Fire Co. and entered the building with his partner, Dennis Fulton. The pair were on the third floor when it's believed they were suddenly overwhelmed by a huge burst of flames known as a "flashover."  

Fulton escaped by diving off the balcony and sliding face first down a ladder.

But Falkenhan did not make it out. 

The 43-year-old husband and father of two signaled a "Mayday" distress call at 6:47 p.m. and rescue workers quickly returned to the third floor. WBAL Radio later posted audio of the radio calls. They pulled Falkenhan out of the building, down the ladder and performed advanced life support measures. He was transported to St. Joseph Medical Center, where he was pronounced dead.

County Executive Kevin Kamenetz and Fire Chief John Hohman announced Falkenhan's death to the public shortly after 9:30 p.m., an announcement that was felt by firefighters throughout the state.

“He was extremely well liked and well known throughout the fire service. … He was someone who was very deeply involved in the fire service, as a lifelong passion,” said Elise Armacost, a spokeswoman for the Baltimore County Fire Department. “His death has been a source of great sadness and grief here today.”

Two residents were also injured in the fire and taken to area hospitals for burns. Approximately a dozen residents were displaced by the fire. The manager of the Towson Crossing apartments has not returned calls for comment.

Fulton, meanwhile, suffered “some cuts and bruises,” Armacost said.

On Thursday morning at the Lutherville Volunteer Fire Co. Fulton's left hand was wrapped and his upper lip was bandaged. But his physical pain was nothing compared to the sadness he and his fellow Lutherville volunteers were feeling.

At their Bellona Avenue station, dozens of volunteers gathered to grieve with one another, but were too grief stricken to speak publicly about their friend.

Fire officials are still investigating the phenomenon of a “flashover,” which would have hampered rescue efforts, though Armacost said it hadn’t been fully determined that a "flashover" did occur.

“When you have a fire obviously objects in the fire become super heated,” Armacost said.  “As objects become heated they produce flammable gases. The flashover occurs when there’s a sort of tipping point at a certain temperature when those gases simultaneously ignite.

“It was described to me a little bit this morning like when you throw fuel on a charcoal fire,” she continued.

Del. Jim Malone described a flash-over to his fellow House of Delegates members while on the floor of the General Assembly Thursday morning: "For those of you who don't know what a flash-over is, that's when all the smoke and gas in the room becomes flames."

The fire department has requested additional support in the investigation from the Federal Bureau of Alcohol, Tobbaco, Firearms and Explosives.

There is still no known cause for the fire.

“The fire investigators are out at the scene as we speak, continuing to look at all the physical evidence,” Armacost said Thursday afternoon. “They’ll talk to people who were witnesses to it as well—that’s what they do whenever there is a serious fire.”

Hohman, who announced Falkenhan's death Wednesday night, spent the day with Falkenhan’s family, including his wife, Gladys, and their two sons. 

She said she trusts that the firefighters on the scene did everything to save her husband. She also knows he would have done the same for them.

“He cared for everyone that he ever met,” she said. “Everyone he met was his friend and was so loved. We’re all going to miss him.”

 Stay with Patch as more details from the investigation become available. 

Patch editors Bryan Sears and Ron Snyder contributed to this report.