Story highlights "Our mission is to resolve this situation peacefully," says spokesman

Charles Poland Jr. was killed when he tried to shield children from a gunman

Police say the gunman boarded a bus, killed Poland and grabbed a boy

The suspect is holding the 5-year-old hostage in an underground bunker

A memorial service was held in southeastern Alabama on Sunday for a school bus driver hailed as a hero.

Charles Albert Poland Jr., 66, was killed last week when he tried to shield children from a gunman, who authorities say boarded a bus, shot Poland and grabbed a 5-year-old boy.

The suspect and the child remained barricaded in an underground bunker in Midland City on Sunday, as the standoff stretched into its sixth day.

"I'm sad to see you gone. You didn't deserve to die, but you died knowing you kept everyone safe," read a letter from a student.

Suspect Jimmy Lee Dykes, 65, is a Vietnam War veteran and retired truck driver.

Donny Bynum, the superintendent of Dale County schools, read the letter and several others at Poland's service, which was held at the Ozark Civic Center.

"Being on your bus has been some of the best times of my life," said a second letter.

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"I will miss your big, smiling face," read a third.

Poland was remembered as a loving husband, father and "paw-paw," who would do anything for his grandchildren. He was the type who brought students ice water on hot days.

According to authorities and witnesses, on Tuesday at about 3:40 p.m., Poland was shuttling children from school to their homes when he dropped students off and the suspect boarded the bus.

The gunman demanded that Poland hand over two children. Poland refused, blocking access to the bus's narrow aisle as at least 21 children escaped out of the back emergency door, authorities said.

The gunman shot Poland four times, killing him, grabbed the kindergartener and then barricaded the himself and the boy inside a nearby bunker.

"Charles Albert Poland was a hero," Bynum said.

Hot Wheels and Cheez-Its

The suspect in the case has been identified as 65-year-old Jimmy Lee Dykes, who has been described by neighbors and officials as a survivalist with "anti-government" views.

Authorities have said little about what, if any, demands have been made by Dykes. They said there is no connection between the suspect and the child.

"We continue to maintain an open line of communication with Mr. Dykes. He continues to make the environment as comfortable as possible for the child," according to a statement Sunday from FBI spokesman Paul Bresson.

The statement was released after authorities postponed a news conference.

"Throughout the day, Mr. Dykes has continued to allow us to deliver food, medicine and comfort items to the child. Some of those items we have delivered include a red Hot Wheels car and some Cheezits crackers," Bresson said.

The 5-year-old suffers from Asperger's syndrome and attention deficit disorder, said State. Rep. Steve Clouse.

Dykes has told authorities he has blankets and a heater in the bunker, and authorities have previously said the bunker -- built 4 feet underground -- has electricity.

Negotiations are being carried out between the suspect and authorities through a 60-foot plastic ventilation pipe that leads from the bunker, authorities said.

It's unclear whether Dykes has access to news reports about the standoff.

"Our mission is to resolve this situation peacefully for both the child and Mr. Dykes," Bresson stressed in his statement.

Standoff a focal point

The standoff has become a focal point for the people of Midland City, a town of about 2,300 northwest of Dothan.

Signs posted around the town and at the church urge people to pray for the boy.

During a vigil Saturday outside the town hall, Michelle Riley called on Dykes to release the boy.

"He just needs to know that ... everybody makes mistakes," she said. "Everybody's been through life events that changes them, but (the boy is) innocent. You know, let him go home to his mother. Let him go home to his grandparents. Let him come out to the community. Let him go back to school and be with his friends."