Story highlights The man ran into the church with his clothes and body aflame

He was later found dead; the church pastor died at a hospital

A third person, a woman, was critically injured

It's not known how the man came to be on fire

Members of an Ocean City, Maryland, church are mourning this week after a bizarre fire left two people dead, including the church's longtime pastor, and a woman critically injured.

The blaze started Tuesday when a man -- his clothes and body aflame -- entered St. Paul's by the Sea church in a section where services are provided to the area's needy.

"Somebody tried to put him out and then the building caught fire from there," a witness told CNN affiliate WJLA

The fire, possibly helped by the use of an accelerant, spread quickly, according to fire and police officials.

The man, identified by Ocean City Police as 56-year-old John Raymond Sterner, was found dead inside the building by firefighters. The church pastor, the Rev. David Dingwall, was found unconscious on the second floor of the church amid "heavy smoke and heat conditions," authorities said. He later died at a hospital. A third victim, a woman, was critically injured, police said.

It's not yet clear how Sterner came to be on fire.

The Rev. Canon Heather Cook of the Episcopal Diocese of Easton told The Baltimore Sun that a church parishioner and volunteer at the food bank that operates out of the church rectory were preparing to open when the man came in, screaming for help.

"I'm heartbroken. I'm sick," church organist Shirley Hailey told WJLA. "It's just horrible. Absolutely horrible."

Fire Chief Chris Larmore called it "a very tragic day for our community."

The beach town is a family-friendly weekend destination in the summer for much of the Washington area.