NEWARK, N.J. (CBSNewYork/AP) — A yard full of plastic flowers and other decorations helped ignite a fire that led to the deaths of six people, including two children, in Newark on Sunday, authorities said

The artificial flowers were found in front of the house and on the porch, Acting Essex County Prosecutor Carolyn Murray told reporters Monday.

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“These flowers are highly flammable when ignited and served as a conduit,” Murray said.

Murray said the fire was started by an unknown heat source. She said no criminal intent has been found, but is asking for the public’s help to provide “any information anyone might have about a match, any kind of cigarette or something like a lighter.”

The home on South 15th Street became engulfed in flames just before 4 a.m. Sunday before the blaze spreading to another home, destroying both buildings.

Plastic flowers are seen in the yard of a Newark, NJ home where six people were killed in a fire on June 15, 2014. (credit: Monica Miller/WCBS 880)

Plastic flowers are seen in the yard of a Newark, NJ home where six people were killed in a fire on June 15, 2014. (credit: Monica Miller/WCBS 880)

“Everything went up in flames really, really fast,” neighbor Jana Diggs told CBS 2’s Diane Macedo. “We heard ‘pop, pop, pop.’ Next thing, I looked out the window, saw the flames from the backyard.

“We knew people were in there,” said witness Erica Simmons. “It was a woman in the back screaming for help, and it was nothing no one could do about it.”

Investigators said the home had no smoke detectors. There was no way out of the front because the family had installed some kind of security device on their windows, CBS 2’s Christine Sloan reported.

Iris Sydney stood outside the burned-out residence later Sunday, clutching a framed studio portrait of her grandson, 15-year-old Stephon Sydney, and his mother, Noreen “Michelle” Johnson, who died in the blaze.

They were supposed to meet the boy’s grandmother for a Father’s Day service at the Solid Rock Church, where Stephon’s father attended services before he died two years ago in a bicycle accident in Newark. But they never showed up.

When Sydney returned home from church, a sheriff’s deputy was standing at her door and gave her the sad news that her grandson and his mother were killed in the fire, along with four others.

“I buried my husband, I bury my son, and now this is my grandchild,” she said. ” I feel it. I feel it in my heart. This is a sad day for the Sydney family. It is.”

Sydney, 77, said the boy and his mother were visiting from Crawford, Georgia, and were staying with Johnson’s relatives at the house, now black and charred, when the fire broke out.

Also killed in the fire was Salome Stewart and her husband, Reginald Stewart, both 58, and Salome Stewart’s sister, 47-year-old Natasha Kinsale, who all lived in the house. Another visiting family member, 11-year-old Zion Forbes, of East Orange, also died.

Neighbor Marla Franklin defended the family’s use of the plastic flowers.

“They celebrated their home,” she told Sloan. “They had the right to decorate their home however they saw fit.”

Interim Mayor Luis A. Quintana said he will introduce an ordinance to place limitations on the use of the plastic flowers for outside decoration.

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“Some of these things, decorations, are cultural,” he said. “You miss home, winters come, and you’re thinking of back home. And you decorate like you’re back home.”

Everyone in the second home managed to escape safely, authorities said.

Neighbors said they heard what sounded like an explosion just before it erupted.

“I did hear last night, a boom,” said neighbor Stacy Kowlessar. “I didn’t come outside though. I stayed in my bed. I thought it was fire crackers or something.”

Some witnesses said they called 911 immediately, but claim operators took several minutes to answer their calls and send help.

“It was already in flames for a long time by the time they got here, and then when they got here, they didn’t respond and try to put the fire out fast enough,” said witness Iminah May.

Other sources told CBS 2 that authorities received the first call at 3:51 a.m. and responded within minutes.

Meanwhile, neighbors said the community as a whole is suffering a loss. Many said the family constantly went out of their way to help others.

“It’s sad when you lose kids, when you lose lives like that,” neighbor Mark White told 1010 WINS’ Derricke Dennis. “It’s unexplainable.”

“They were just really good people,” another neighbor said. “They would donate toys and stuff for the kids and book bags and stuff. Good people.”

Quintana, who went to the fire scene as firefighters worked to control the blaze, said in a statement Sunday: “Our heartfelt condolences go out to the family and friends of our six residents whose lives were taken by this horrific fire.”

A small storefront church called Tree of Life Ministries, on the other side of the home where the six died, appeared undamaged. Neighbors gathered outside the home, many in their Sunday church clothes, shaking their heads at the loss of so many lives.

The Rev. Thomas Ellis lives in the neighborhood and stopped by to offer his support.

“For the city of Newark, this is a sad and tragic day,” he said. “The community is hurting.”

He and about 15 others held a prayer vigil Sunday evening.

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