WEYMOUTH (CBS) — An aspiring Massachusetts firefighter driving home from a firefighter’s agility trial had the chance to prove her skills.

As she drove home from the test, she saw a building on fire in Weymouth, but didn’t see any firefighters.

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Jackie Giacchetti says she stopped immediately and went to work in the fire-engulfed buildings on Washington Street Thursday afternoon.

“I actually had just left my future office in Braintree. I was on my way home and I saw thick black smoke coming from the building behind me,” Giacchetti said.

Firefighter in training Jackie Giacchetti. (WBZ-TV)

She says the reason she stopped was pure instinct.

She believes that the two women inside the nail parlor didn’t know the building was on fire. She adds that there was a man and a woman in the house next door.

“I just ran in and told the women to get out. And then I went over to the next door neighbor’s house, trying to help them and get them out as well,” she said

The firefighter in training says it was instinct that made her stop to help.

“This is the career that I’m going for and again, in situations like this everyone’s running out I’m the one running in,” she said. “I wanted to make sure everyone was safe.”

Giacchetti found herself at a three-alarm fire that would destroy the building housing Damien Hardwood Floors, the house next door, and the garage in-between.

“Shortly thereafter Weymouth arrived and mutual aid,” she said. “They put out the fire as quickly and as safely as they could.”

Weymouth Firefighter fighting the flames. (WBZ-TV)

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The fire needed crews from Quincy, Rockland, Hull, Hingham, Braintree, and Randolph, as well as Weymouth before it could be put-out. Giacchetti says the crews from those cities and towns worked well together.

“I feel they should all be acknowledged for the great work they did. I know they worked hard, were exhausted. They were sweating and within a couple of hours they had both buildings under wraps,” Giacchetti said.

Weymouth Fire Chief Keith Stark had a good word for Giacchetti.

“You don’t want to be inside a building when it’s on fire, so it’s a great job by that lady,” Stark said.

The Weymouth buildings after the fire was put out. (WBZ-TV)

The investigation shows that the fire was caused by “spontaneous combustion” from a vacuum stored in a van parked in the garage at the location.

One firefighter was injured fighting the fire, but Stark says the firefighter will be okay.

For her part, Giachetti says she, “Wants to be there for people and save lives to the best of my ability.”

Jackie Giacchetti. (WBZ-TV)

She also says it took her nine years to get on as a firefighter and plans to attend a firefighting academy in the fall.

She says she’s wanted to be a firefighter most of her life, and even though she gained real life experience Thursday, she doesn’t believe what she did was heroic.

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“I don’t feel that I’m a hero and I don’t feel that I saved any lives. I just did what I thought was the right thing to do at that time,” she said.