A woman and two children were killed and a third child was critically injured in a Tampa house fire that also injured a firefighter early Tuesday, authorities said.

According to Tampa Fire Rescue, a neighbor saw smoke coming from the home at 3720 E. Paris St. just after 4:30 a.m. and called 911.

When crews arrived, the smoke was overwhelming and the home was engulfed in flames.

Fire officials say the fire started with an overloaded power strip and the home did not have any smoke detectors.

"As firefighters went in and we continued to pull out more victims, more support was called in," Tampa Fire Rescue spokesman Jason Penny said. "So we called in a second alarm."

Three of the victims - Emjay Jackson, 3, and Reshard Ashley and Romello Jackson, both 8 - were transported to local hospitals. Emjay and his cousin, Reshard, later died.  Romello, Emjay's brother, was taken to the hospital, where he is on life support.

Sheryl James, 61, grandmother to the three boys, died at the scene.

Neighbor Ariel Dunlap said her father was the one who noticed the smoke and tried to wake the sleeping family up.

"My dad -- beating on windows, beating on doors, trying to get them to wake up," Dunlap said. "He's yelling 'Wake up, wake up!' "

Fire officials say the family most likely didn't realize what was happening until the home was already filled with thick smoke.

James and two of the children were found together in a back bedroom. Fire officials said one of the boys was found separated from the group in what appears to be a desperate attempt to get out.

"They found one of the victims in the bathroom which gave us the understanding that maybe they tried to get out the bathroom window but were unable to because of those burglar bars,” said Milton Jenkins, Tampa Fire Marshal.

The boys' aunt, Thomisina Fletcher, joined other family members at the scene on Tuesday afternoon.

"I came from Lakeland doing 100 mph," Fletcher said. "If the police came behind me I would've thrown my hands up and said this is what I was racing to."

A firefighter was taken to an area hospital with heat exhaustion. He is expected to be OK.