Eighty-six-year-old Harry Claussen doted on his wife Pearl, 81, who had Alzheimer’s disease.

Every day it was the same routine. He helped her dress, made their bed, fixed their meals, washed dishes and in the evening took her to the Chalet Restaurant on West 38th Avenue, where she had soup while he had bacon and eggs.

“He took really good care of her,” said neighbor Shannon Spencer, 54.

At 3 a.m. Saturday, Harry Claussen tried desperately to save Pearl’s life.

He failed, but not before repeatedly risking his own life by entering and re-entering the home with black smoke billowing out the back door.

When Spencer saw him come out of his home at 3878 Utica St., where he and Pearl had lived together for more than 60 years, his face was coated with soot and he had only boxer shorts on. He was gasping for air.

“He was frazzled. He kept saying, ‘I can’t get to her,’ ” Spencer said. “I wouldn’t let him go back in. The flames were too intense.”

Spencer, who lived next door to the Claussens for 21 years, helped Harry get inside her car in her garage because she was afraid that flames leaping out of the Claussens’ windows would ignite her house. She brought him warm clothes.

The Claussens were dog lovers, who always spoiled their three pets. On Saturday morning, Bugsy and Theodore got out safely but their Pomeranian “Lucky” was killed.

When firefighters arrived, they went into the burning home and carried Pearl out and tried unsuccessfully to resuscitate her, said Lt. Phil Champagne, Denver Fire spokesman.

The cause of the fire is under investigation. One possible cause was a portable heater, Champagne said.

“It’s just a nightmare this time of the year,” he said.

People often leave combustible materials near heaters and they ignite, Champagne said.

“A lot of times they tip over and some older models don’t have automatic turn-off mechanisms and they continue heating,” he said.

The Claussens were ardent Denver Broncos fans. They had a sign on the front porch of their small, green, one-story house that said, “No. 1 Bronco Fan.”

Harry was a sturdy man who worked well into his 80s at a warehouse. He bought his home in 1950 for $10,000, Spencer said. He did a lot of manual-labor jobs throughout his life. He always shoveled snow out of his neighbors’ driveways and sidewalks and mowed Spencer’s lawn.

“He is a strong man; very independent,” Spencer said.

Pearl was a feisty woman. The couple had a son and a daughter, who rushed to the home early Saturday.

“They were the best neighbors,” Spencer said.

Kirk Mitchell: 303-954-1206 or kmitchell@denverpost.com or twitter.com/kmitchellDP or blogs.denverpost.com/coldcases.