The NYPD has two men in custody: Julio Salcedo Contrer, who rented the home in the Bronx that police say was under investigation as a marijuana grow house; and 32-year-old Garivaldi Castillo, of Washington Heights, who is facing two counts of criminal possession of marijuana.
"What do you have to say to these firefighters who are here for their losses?" a reporter asked.
Garivaldi Castillo smirked at the dozens of New York City firefighters who were standing in stony silence as detectives led Castillo to court Wednesday night.
Wednesday morning at Battalion 19, they hung bunting, saluted, and started to say goodbye to their chief Michael Fahy. He was a 44-year-old father of three, a trained lawyer, and a friend.
"Michael Fahy was the nicest guy out of all the nice guys anyone has ever met," said Capt. Brendan Deehan, FDNY Engine 47. "His family was his priority and he loved them more than anything."
Video obtained by exclusively by Eyewitness News shows their frantic attempts to save Fahy's life Wednesday morning, after a giant piece of roof landed on top of him.
Cops say the building on 234th Street was teeming with pot plants and was a so-called marijuana hot house.
Eyewitness News obtained a picture of a van in the driveway days earlier, from which a neighbor saw blue barrels unloaded and brought inside, possibly holding highly flammable liquid fertilizer.
Only a few months ago, the DEA warned of the dangers of grow houses which use "explosive materials such as propane and butane...that pose clear hazards to first responders."
"The propane is used for the CO 2 converter that will increase the production of the lab and that added to faulty wiring makes any indoor grow an accident waiting to happen," said Jonathan Wilson, DEA Special Agent.
Police say they'd already been investigating Castillo and Julio Salcedo Contrer, who allegedly ran from the home after the blast. They tracked him down in New Jersey, where he's awaiting extradition back to the Bronx.
"We are devoted to getting everyone who was in involved and I'm very certain we will, a lot of effort bringing them to justice," Mayor Bill de Blasio said.
PHOTOS: Explosion in the Bronx