WORCESTER, Mass. (WHDH) -- A fire broke out late Saturday afternoon at an apartment complex in downtown Worcester. Rick Renauld was helping a friend move when flames broke out.

“We came down with a load, looked up and the whole windows were covered with flames,” said Renauld.

Renauld ran back inside, hoping to help.

“Took off my sweater, ran, kicked open the second floor door, got everybody out. There's flames going over me, smoke everywhere, you know, I was just trying to find bodies because I thought there were kids in there,” he said.

Fire investigators said as many as six apartments were damaged. More than a dozen are now without a home. Anne Marie Sagan said the fire started in her sister's home.

“All I know is that they were doing laundry, supposedly her husband went to get some beers and it was after that the alarms went off,” said Sagan.

No one inside the building was hurt, including Sagan’s sister, but she lost her cat in the fire.

“I just keep thinking about the cat, hoping it was quick for the cat and that it didn’t suffer too much. I’m still taking it all in,” she said.

Fire investigators remained at the apartment late into the day Saturday, but so far they haven't found a cause.

“I’ve never been more scared in my life. I’m still shaking,” said Renauld.

Renauld said the smoke was so heavy he only made it into two rooms and wasn’t able to find anyone. It is unknown when the displaced residents will be able to return home.