SAN ANTONIO -- A fire broke out at the popular Phantom Room bar on the St. Mary's Street strip around 5:15 a.m. Wednesday.

The San Antonio Fire Department said investigators are trying to determine a cause of the fire, and the structure is likely to be a total loss.

KENS 5's crew at the scene reports firefighters were working to control the blaze for more than an hour.

Video from the scene showed large flames visible from a block away that seemed to engulf part of the structure.

San Antonio Fire Department Chief Charles Hood said crews were initially concerned that the fire would also spread to a nearby condominium complex. However, he said no other structures in the area sustained major damage.

Many of the firefighters responding to this incident were near the end of their 24-hour shift, according to Hood.

Firefighters were also working to clear hot spots, and no injuries were reported.

Most of the damage was in the outdoor patio area. Stephanie Martinez, who works across the street, said Tuesday nights are popular at the bar. The fire starting just a few hours after it closed early Wednesday morning.

"I looked on Facebook and all my friends who attend Phantom Room on Tuesday nights are ok," Martinez said.

Violeta Aguinaga lives in the area and said, "I've been here a few times but wanted to come again."

St. Mary's has been gaining popularity. The owners of the Phantom Room also run other bars in the area. The people who live and work in the neighborhood noticing more homes being built and businesses opening up attracting a younger generation to the area.