"I wanted to give back to the community and I thought this is the best thing I can do," Hernandez said.
Hernandez started on the altar in September. She used a ladder to reach the top.
"People couldn't understand how come I was putting a lot of work, a lot of effort and money," Hernandez said. "But I thought this is making me happy because I was sharing something to the community."
Day of the Dead is meant to remember lost loved ones. It's celebrated on November 1 and 2.
"There's always been a misconception that they think we are celebrating death, what actually we are celebrating life," Hernandez said.
She said she put out a request on social media for anyone who wanted to include their deceased loved ones on the altar. She received about 250 photos.
"People we have lost is part of our history. It's part of who we are, where we are coming from," she said.
There are many ways people observe the holiday. Laura Trejo, who works for Latinos Progresando, said her family spent Día de los Muertos at her grandmother's gravesite growing up.
"You would bring flowers, a lot of the cempasúchil, other things, other foods that she loved since that is part of the celebration, since the idea is that you are welcoming back the spirits of those who have passed," Trejo said.
Cempasúchil, or marigolds, are used to decorate altars and tombs.
Día de los Muertos stretches back centuries in Mexico to its indigenous roots. But Hernandez said you don't have to be Mexican or Hispanic to make an altar for your loved ones.
"We don't want to feel that our loves ones are gone forever," Hernandez said. "So that's the most important thing that we still remember that we're not forgetting about them."
Hernandez plans to begin taking down the ofrenda on Wednesday. She said she's hoping it will only take a day.