CONCORD — Concord fire officials said they are investigating the cause of a two-alarm apartment fire early Saturday morning that left a man with life-threatening injuries.

The fire broke out just before 2:30 a.m. at The Pines of East Concord apartment complex at 20 Bog Road.

Officials said they rescued a man found in a third-floor apartment.

The burn victim was brought to Concord Hospital and then airlifted to a regional burn center.

A second resident, possibly suffering from smoke inhalation, refused treatment at the scene, officials said.

According to city tax records, the Tarbell Family Revocable Trust owns the 24-unit apartment complex, built in 1990.

The three-story, wood-frame property with brick veneer is assessed at $3.7 million.