Firefighters are still investigating the cause of this fire following a busy Fourth of July holiday.
Oakland firefighters raced to the house fire around 4:30 a.m. Neighbors shot and shared cellphone video along Hayes Street near Seminary Avenue where the incident occurrerd.
"We hit a second alarm, which automatically doubles our units on scene. We had reports of people trapped," Oakland Fire Department Battalion Chief James Bowron said.
ABC 7 News spoke with a woman who lives inside the home. She was one of the first to see the fire and she believes it started in the front of the house. "They heard some popping, they heard some issues realized that there was fire and they were able to get themselves out," Bowron said.
A 21-year-old woman suffered facial burns and smoke inhalation, but is said to be doing OK at the hospital. Two people lived in the lower unit and four people lived in the second story of the duplex. They were shaken and eager to see the woman in the hospital.
Residents say a Fourth of July party was held on the block, but it's unclear if fireworks may have sparked the fire. "Investigators are on scene and interviewing the occupants of the building and starting to look at the burn patterns to try to really narrow it down," Bowron said.
Oakland firefighters staffed additional crews to cover the busy holiday. Red Cross is assisting the victims.