JANESVILLE, Wis. -- Rock County officials are trying to piece together the cause of a fatal Saturday morning fire that happened on Janesville's northwest side.

When the police arrived at a house in the 300 block of North Palm Street just after 8 a.m. on Saturday, they found a tragic scene. A family had lost everything, including their 7-year-old son, WISC-TV reported.

Ben Stricker and his girlfriend Michelle White live across the street from the victims' home. They awoke Saturday morning to find their neighbor's home in flames.

"The neighbor was outside yelling. At first I thought she locked her keys in her house, but then I saw her break a window, and then all the smoke come out," said Stricker.

"Flames were literally shooting out of the upstairs. They were just everywhere," said White. "I don't know, I just saw a little boy and knew I should grab him, because he was just wandering around the yard."

When Janesville police arrived, they were informed that there were people still inside.

"A young child woke up his father to let him know about the fire. The father took that child outside and called 911," said Lt. Tom Wolfram of the Janesville Police Department.

Officials were informed that a 7-year-old boy was trapped inside, but there was no way for police to reach him.

"It's probably the toughest thing an officer can do is knowing someone needs help and not being able to go in and give them the aid that they need," said Wolfram. "But, when there's that much smoke, they're better off waiting for the fire department or they'd succumb to it themselves."

Despite efforts of rescuers and the family, the 7-year-old was killed.

"The grandmother actually threw her whole body at the front door and broke the front door down to get in, and broke out windows. But the smoke, it was just pure black. You couldn't even see in there," said Michelle White.

A 2-year-old boy also trapped in the house might have a chance.

"A 2-year-old was Med Flighted to Milwaukee. So we know inside the house, the conditions would have prevented anyone from getting through it. The father himself couldn't go in," said Wolfram.

Neighbors said that it's typically a quiet neighborhood, and the family often kept to themselves. One neighbor said that the 7-year-old often came over to play with his dogs. Like the entire neighborhood, he said he's shocked by what happened, WISC-TV reported.