The flames were shooting out of a three-story Lehigh Valley home on South 5th Street in Emmaus around noon Sunday.
The smoke was heavy and the fire was moving fast but that didn't stop neighbor Michael Aldinger from running in to help.
"It blew up, the windows blew out. It was burning," Aldinger said.
Aldinger was able to pull two people out, but others were still trapped inside the building which has five apartments.
"I heard a couple of people screaming, yelling, crying. [I was] just trying to help them out. I wish I could have done more, but I couldn't," Aldinger said.
Firefighters rushed to the scene and went to work breaking windows and attacking the fire.
It took them some time to get it under control.
In the end, four people who were unaccounted for were found dead.
Their remains were burned so badly dental records and DNA tests will be needed for the coroner to positively identify the victims.
Tenant Bobby Taylor lost his longtime girlfriend Maria in the fire.
The McDonald's restaurant where he works started taking up a collection for Taylor.
"It's devastating. We're a family here. We all know Maria. Bobby's one of us. It's just devastating for us," McDonald's manager Jackie Grub said.
14-year-old Brooke Woomer says her father just arrived to pick her up for work right when the building went up in flames.
"He came a minute and half before the explosion happened, so if it wasn't for him, I wouldn't be standing here talking to you. My dad is my lifesaver. He's my hero," Brooke said.
Other residents were taken to the hospital with minor injuries.
"It's unfortunate that life had to be lost, but I hope everybody else is safe," neighbor Janice Engleman said.
Years ago, the building housed the well-known Ritter Funeral Home owned by Kelly Furlong's family.
She grew up across the street from the place, which meant a lot to her.
"It's just part of my family, it's part of the community. It's always been there and now it's gone," Furlong said.
The Emmaus Police Department is literally around the block from the scene where investigators worked to figured out the cause of this deadly fire.
Homes on each side of the building were evacuated because officials are afraid the structure will collapse.
"Well, I don't like leaving my house but I have to. I hope the wall doesn't fall," evacuee Roger Bean said.
The Red Cross is helping the residents who were forced to evacuate.
Meantime, Brooke Woomer says she is grateful that she survived, but she is heartbroken over her neighbors who did not.
"It was just horrible and all those people who passed, I stayed up last night to pray for them. It hurts so much to know so many people died from something like this that you never expect to happen to you," Brooke said.