PINEVILLE, N.C. -- A fire that killed a 20-year-old firefighter in a strip mall Saturday night was started by a lightning strike, according to officials.

Dozens of people left flowers, cards and other mementos at Pineville Volunteer Fire and Rescue in memory of firefighter Richard Sheltra.

Sheltra died in a Saturday night fire at a strip mall in Pineville. Sheltra's death was determined to be due to smoke inhalation.

"It's a difficult time for all of us, but we will remain strong as a town and as a fire service," Pineville Fire Chief Mike Gerin said. "Richard was our rookie of the year in 2015, and had the most training hours. He did this as a volunteer."

Melissa Hempel visited the department to thank firefighters for their service.

"They are the ones that are there in our worst times so it's only fitting that we try to be there for them in their worst time right now," Hempel said.

She didn't know Sheltra personally, but she heard a lot of praise for the 20-year-old firefighter who was named the department's "Rookie of the Year" back in January.

"Fun-loving, lives every minute to the fullest, very compassionate," she said.

Huntersville Fire Department's Bill Suthard's acting as spokesman for Pineville.

He said the community created a memorial adorning one of the fire trucks after children at a local church wrote letters to the firefighters.

"The letters say 'thank you,'" Suthard said. "They say 'thank you for the service you provided the community.'"

Fire trucks from other departments including Charlotte and West Mecklenburg are taking over Pineville's shifts for the next few days as the department's firefighters take time to mourn Sheltra's death.

A memorial service will be planned for the coming days.