A Bronx man killed in an explosion sparked by a homeless crack addict stealing a kitchen stove was battling multiple sclerosis in the months before the fatal blast, his grief-stricken brother told the Daily News.

Ronald McCallister, 60, can be seen on surveillance video talking with a firefighter in a 16th-floor hallway outside his apartment in the Boston Secor Houses in Baychester on Jan. 23. McCallister ducks a second before a red plume of fire erupts and fills the screen.

When the smoke clears, the hallway is full of rubble. McCallister died at a nearby hospital after the ceiling collapsed on him.

Ronald McCallister, 60, can be seen on surveillance video talking with a firefighter in a 16th-floor hallway moments before the explosion.

Obtained by Daily News

Ronald McCallister, 60, can be seen on surveillance video talking with a firefighter in a 16th-floor hallway moments before the explosion. (Obtained by Daily News)

“I wish I could take my brother’s place. I wish I was there to help,” said Terry McAllister, 59. “They weren’t able to recognize him. All I can think of is just like the pain that he went through, that he suffered.”

Terry used a cane to walk and that might have factored into him not getting away from the blast, his brother said. “I don’t know how he ended up in the hallway,” he said. “I don’t know if he was trying to leave and maybe smoke.”

Leaking gas spread to the 17th floor, where it ignited.

Theodore Parisienne / New York Daily News

Leaking gas spread to the 17th floor, where it ignited. (Theodore Parisienne / New York Daily News)

Samuel Calderon, 55, is facing murder charges for the explosion. Calderon told police he went to the building to steal his ex-girlfriend’s stove and sell it for a gram of crack, according to court papers. He taped a blanket over the hole and fled after he heard and smelled gas, according to the criminal compliant.

Video shows Calderon trying to lug the stove out of his ex-girlfriend’s apartment on the 13th floor of the building on Bivona St. near Reeds Mill Lane before abandoning it, according to the complaint.

The leaking gas spread to the 17th floor, where it ignited, the complaint states. FDNY firefighters were investigating reports of a gas smell on the top three floors of the 17-story building when right before the explosion, FDNY officials said.

Five other people were taken to local hospitals for treatment, including a 37-year-old man found unconscious in critical condition, cops said. An FDNY firefighter was also among the injured.

Samuel Calderon is escorted from the 47th precinct house by NYPD detectives on Jan. 28.

Kerry Burke/NYDN

Samuel Calderon is escorted from the 47th Precinct stationhouse by NYPD detectives on Jan. 28. Calderon, 55,  is facing murder charges for the explosion. (Kerry Burke/NYDN)

“I’m still in shock,” Terry McAllister said. “How did (Calderon) have access to this apartment? And to take out a stove? That’s a lot of work to go ahead and do that when you could have probably went with a TV or something else.”

The brother said he started getting calls and texts from numbers he didn’t recognize after the explosion and worried he was being inundated by scam calls. Then he saw news reports about the explosion and when his brother didn’t answer the phone he realized something tragic had happened.

Born in Harlem, Ronald McCallister moved to the building in the 1990s. He never married or had children and was diagnosed with MS last year, his brother said.

“He worked from home and he just recently retired. Due to conditions of MS he was unable to work. Just looking back in time he was always a very quiet and private person,” Terry McCallister said. “But the irony was that he was well-liked in the community. Whenever I went by to visit him, someone was either cooking for him, helping him clean or hanging out.”

“He was just very authentic, very humble, comforting towards others,” he added.

A massive fire tears through the top of the NYCHA high-rise on Bivona St. early Saturday, Jan. 24.

FDNY / X.com

A massive fire tears through the top of the high-rise on Bivona St. early Jan. 24. (FDNY / X.com)

Ronald was an avid reader who loved to walk, dabbled in cooking, and traveled from time to time, his brother said.

Even though he was very private, he opened the door for anyone who needed help.

“He always wanted to offer advice or help an individual,” the brother said. “I can’t emphasize that enough. He was just that type that went to help others before he would even help himself.”