An unknown number of animals died Monday in a fire at a Lawrence pet store.

Lawrence emergency crews responded to fire and heavy smoke at Pet World, 711 W. 23rd St., at about 12:30 p.m. The store was filled with smoke for about 30 minutes before firefighters began removing some animals from the building, located in the Malls Shopping Center. Several veterinarians and a large crowd of bystanders gathered in the parking lot to offer assistance.

Rescue workers brought out 20 to 30 tarantulas, many fish, a large python and other reptiles. In addition, some feeder rats, a few hamsters and gerbils stored in a separate structure were alive.

Other animals died in the fire, Lawrence-Douglas County Fire Medical Division Chief Eve Tolefree said. Co-owner Sherry Emerson, who opened the store 27 years ago, said “no mammals or birds survived.”

The store had been boarding small animals at the time of the fire, Emerson said. She had not had a chance to call the pet owners as of Monday evening.

Emerson said she was unsure how many total animals survived, but that the store’s locally famous 13-foot python, Goliath, was among the survivors. Pet World’s tortoises also were safe, as they had been taken earlier to their summer home at a tortoise farm north of Lawrence, Emerson said.

Pet World had recently teamed up with the Lawrence Humane Society by housing adoptable kittens at the store for the summer. Eight of the kittens were adopted over the weekend, but the one remaining kitten died in the fire, Emerson said, choking back tears.

The store’s double yellow-headed parrot, Fletcher, who had been greeting Pet World customers since 1994, also died in the blaze.

No animals were hurt by flames, Emerson explained. The fire’s animal victims all died because of smoke inhalation.

Emerson said firefighters told her the fire was “hot and fast,” but the cause has yet to be determined. Pet World has a fire alarm system that notified the fire department of the smoke, but the building, which Emerson said is rented, was not equipped with a sprinkler system.

Pet World was closed for Memorial Day, and Emerson said staff were participating in a 5K trail run and retreat at a nature preserve north of town. Through the sadness of the day, Emerson said she found relief knowing employees were “together and safe” when the fire broke out.

“I’m trying to focus on the fact that of all times this could have happened, no one was in the store to be injured,” Emerson said.

About five local veterinarians administered oxygen to the reptiles — turtles, lizards and snakes — as they were brought out. About 30 Pet World staff members — in matching “Pet World 5K” T-shirts and covered in mud — assisted by cleaning soot off the animals.

Robin Michael, a Baldwin City resident and Clinton Parkway Animal Hospital veterinarian, said she was at the intersection of 23rd and Louisiana streets when she saw smoke, but wasn’t sure at first of its source.

“My heart just sank when I saw it was Pet World,” Michael said.

Michael was on the scene almost three hours. Firefighters began to bring reptiles out of the building at about 1:15 p.m., by which time several more veterinarians had arrived to assist.

Veterinarians assessed each animal’s condition, and some were sent to Gentle Care Animal Hospital for further treatment, Michael said. There, the animals will be treated for skin and eye burns and administered oxygen and fluids as needed, Michael said.

Michael said some of the reptiles were able to survive because they have a different respiratory anatomy than mammals, which allows them to hold their breath for long periods of time. With smoke inhalation, the condition of the animal can worsen after the fact, Michael said.

“They aren’t necessarily in the clear,” she said.

Michael said she was heartbroken by the day’s events.

“I’m ready to go home and cry,” she said as she prepared to leave.

Between the veterinarians and the Pet World staff, Michael said, the surviving animals were well taken care of.

“They’ve got their entire staff here,” she said. “Obviously everybody really cares for the animals, and it’s going to be a very difficult time for them all.”

About 100 bystanders watched as emergency crews tackled the fire and staff worked to resuscitate animals. Many expressed concern for the animals and sympathy for the owners.

Gretchen Lister stood along the yellow tape of the police line with her two sons, Alex and Curtis, ages 9 and 10.

“We’re very sad,” she said.

Lister said in addition to celebrating their birthdays at Pet World, her sons also enjoy the educational programming, such as the school visits and the Animals After Dark event.

“There’s just been so many neat things to bring kids together with animals,” she said.

Lister said the crowd was a testament to Pet World’s place within the community.

“All these people are here for a reason,” she said.

On social media and at the site, many supporters of Pet World and its owners, Tim and Sherry Emerson, expressed grief and a desire to help.

Speaking with reporters late Monday afternoon, Tolefree said there is nothing members of the public can do now other than respecting the feelings of the owners and employees and showing support.

“This is really an emotional time for the owners and the workers,” Tolefree said.

Emerson said she and her husband are taking the situation “one step at a time.”

“As far as reopening, I have no idea,” Emerson said. “We did not see this coming.”

Tolefree said Monday evening that crews were still assessing the extent of the fire damages.