By Ben Brumfield and Steve Almasy
(CNN) — One body was pulled from the debris Wednesday at the site of an explosion at a Kansas City, Missouri, restaurant.
Officials say they cannot be certain that there are no other victims of the explosion, which happened Tuesday evening after a strong odor of gas was reported in the area.
One female employee was reported missing after the blast, but Fire Chief Paul Berardi said it was too early to confirm the identity of the victim, whose body was found near the restaurant’s bar area.
At least 15 people were injured in the blast.
Six people remained hospitalized Wednesday, three in critical condition, Berardi said.
Although only one person was believed to be missing, and one body was found, Kansas City Mayor Sly James said he cannot be 100% sure everyone has been accounted for.
About 30 search personnel were on the scene Wednesday.
The odor of natural gas led to the early closure of JJ’s restaurant, but hostess Deidre Estes and other employees weren’t in a rush to leave, unaware of the danger they were in.
Then, “Boom! And everything was black,” Estes told CNN affiliate KCTV.
The blast ripped the roof off of the restaurant.
“I thought I was going to die. Honestly, I thought I was trapped in there,” Estes told KCTV. “I saw the flames, and I was scared I was going to burn up. And then with all my might, I got this strength and lifted the rubble off.”
A utility crew investigating the odor had suggested that the restaurant close, but gave no sense of urgency or the potential for an explosion.
The mayor confirmed that the fire department responded to a call about the gas odor, about 50 minutes before the blast, but left the scene after being told by the utility company that everything was under control.
“When these situations exist, the fire department defers to the expertise of any utility who is there,” James said.
Debris was stacked 3 to 4-feet high where the restaurant once stood.
“Early indications are that a contractor doing underground work struck a natural gas line, but the investigation continues,” according to the utility, Missouri Gas Energy.
The fire department suspects no “foul play at this time,” Berardi said.
The gas leak started about an hour before the explosion.
People at JJ’s and nearby residents smelled it and alerted authorities. Utility workers came out to inspect, fire department spokesman James Garrett said.
Jennifer Carter, who was in the restaurant, told CNN affiliate KSHB that a man who had a hand-held device came in before the blast and told her and 10 others to leave. Employees had already turned off appliances after smelling gas, she said.
Carter complied. She was just a few blocks away when she heard the explosion.
The gas sent flames a few stories high into the night sky. More than 100 firefighters responded, Berardi said.
Dr. Leonardo Lozada heard the explosion a block and a half away at St. Luke’s Health Systems, where he is chief physician.
“It was pretty loud. I just heard it; it wasn’t that traumatic,” he said.
JJ’s Restaurant was a popular place near Country Club Plaza, an opulent locale with upscale shops and restaurants.
The restaurant’s owner, James Frantze, was in Oklahoma at the time of the blast. A message on the restaurant’s Facebook page made a simple request of patrons:
“Please keep our friends and families in your hearts and prayers.”
CNN’s Carma Hassan and Cristy Lenz contributed to this report.