A Bainbridge woman died in a devastating early morning house fire Saturday on Monte Vista Drive that authorities later said started accidentally in a pantry in the single-family home.

Anne A. Schlee, 83, died of “asphyxia due to inhalation of toxic combustible materials as a result of the house fire,” the Kitsap County Coroner’s Office said Tuesday.

The house fire in the 6500 block of Monte Vista Drive was reported by a neighbor just before 1 a.m. Saturday.

Firefighters found a two-story, single-family home nearly fully engulfed in flames when they arrived.

The two residents — Anne and Sandy Schlee — were asleep at the time of the fire, which was discovered after a smoke alarm went off and her husband went downstairs to investigate.

Sandy Schlee “found fire on the first floor and was unable to get back up to the second floor and get his wife,” said Bainbridge Island Fire Marshal Luke Carpenter.

Firefighters could also not enter the home because of the size of the fire.

“Because of the amount of fire — and portions of the house began to collapse — we could not get into the house,” said Carpenter, who is also an assistant fire chief with the Bainbridge department.

The victim’s body was found at about 7 a.m. Saturday in an upstairs bedroom.

The husband was taken to Harrison Hospital for a medical evaluation, Carpenter said, but no serious injuries were reported.

Nick Allen, a senior at Bainbridge High who lives next to the Schlees, called 911 to report the fire after he saw a flash outside his bedroom window.

“I was just crawling into bed at the time,” said  Allen, 18.

He looked toward his neighbors’ home and saw 10-foot high flames climbing up the east side of the house.

“I could see flames coming out of the pantry window,” Allen recalled.

At that point, his Eagle Scout experience kicked in.

“My first thought: This is entirely out of my league; I need to get the fire deparement here.”

Allen ran back upstairs and called 911. He put on his pants, called out to his parents, grabbed a flashlight and ran next door.

The home where his neighbors had lived for more than 20 years was just 30 feet away.

“When I got there the house was entirely engulfed in flames,” he said.

It sounded like a crackling fire in a fireplace, only much, much louder, he said and he heard glass breaking as windows began to shatter.

He saw Sandy had made it out of the house and the teen did a quick assessment to make sure he was OK.

“I was checking to see if he had any major problems; broken bones, bleeding or burns anywhere,” Allen recalled, and told him the fire department was on the way.

Allen then ran to the front door and kicked it in.

“The hallway was completely engulfed. Flames on the floor, the walls, the ceiling, the furniture,” he said.

The heat started to make blisters on his arm, but Sandy came up to the doorway and Allen put a strong hand on his shoulder to stop him from going back inside.

“He kept telling me, ‘I’m thinking of her.’ I looked back at him and back at the hallway.

“I told him, ‘If you go in there you will die, and, I’m sorry but we have to go,” Allen recalled.

A police officer arrived, took a look at the home in flames, and started cursing. Firefighters came moments later.

Firefighters from Bainbridge, North Kitsap and Poulsbo responded, and island firefighters were on the scene for 12 hours Saturday. In all, about 14 units responded to the blaze.

The fire has been a neighborhood tragedy.

Allen said he’s known the couple his whole life, and described them as warm and loving.

“They were the best couple I’ve ever seen. They were always generous and kind.

“And I remember thinking if my potential mate in the future was a fraction like them, that would be OK,” he said.

Carpenter said — after interviews with witnesses and the homeowner — the cause of the fire was determined to be accidental and probably originated in a pantry used for storage.

The house, which was built in 1975, was destroyed.