(CNN) Support for the only black volunteer firefighter in an upstate New York town continues to pour in after he lost his home to suspected arson within days of receiving a letter containing racial slurs.

A judge Friday entered a not guilty plea on behalf of the suspect, a former volunteer firefighter.

Kenneth Walker said he received a letter in his mailbox Monday demanding he resign from the fire department by the end of the week and that he leave the small town of North Tonawanda. The letter used the N-word several times and said Walker would "regret it" if he didn't resign.

"[Expletive deleted] are not allowed to be firefighters," it said. "No one wants you in this city."

A fire broke out Wednesday afternoon while Walker and his family were away. Two cats in his apartment were killed and almost everything inside was destroyed, said North Tonawanda Fire Chief Joseph Sikora.

Police arrested Matthew Jurado, 39, who lives across the street from Walker, on Thursday. He was charged with second-degree arson.

Jurado "admitted to us that he started the fire," said Detective Capt. Thomas Krantz of North Tonawanda police. But the suspect denied writing the threatening letter to Walker.

"At this point, we have a name that he provided us. However, we are still looking at the possibility that it is in fact he who wrote the letter. It could be this other person but that will be determined at a later date." Krantz said.

Jurado did not have an attorney present when the judge entered the not guilty plea, but he will return to court August 11 to apply for a public defender, said court clerk Faith Elliott.

Jurado is being held on a $50,000 bail, the clerk said. He was booked Friday morning at the Niagara County Jail, according to Beth Dunn of the Niagara County Sheriff's Office.

Bob Brennan, president of the Gratwick Hose Fire Company, where Walker volunteers, said that when Walker showed him the letter on Monday evening he felt physically ill. After the fire, he said, he felt "disbelief and rage."

"It's been a full range of emotions," Brennan said.

Brennan, who is speaking on behalf of the family, said he has known Walker for four years and considers him a close friend.

"He is somebody I could call at 3 in the morning if I was three hours away from home, and he would come and get me," Brennan said.

Ex-colleagues knew each other

The suspect allegedly told police that the fire was not race-related, but that he was upset with the fire department after being removed from his position.

Jurado was removed from the fire department in July for "not meeting the necessary training requirements," said Sikora, the fire chief.

Jurado and Walker knew each other because they had taken some training courses together, authorities said. But Krantz wouldn't go into detail about possible motives for targeting Walker's home.

The town's fire and police department, along with the FBI and New York State Office of Fire Prevention and Control investigated the fire and the letter, which shocked many in the town.

"I told everybody it's appalling to think about what's taking place," Sikora told CNN. "Our city has never had an issue like this. Not in 26 years. Quite frankly, it sickens me."

An outpouring of support

The fire left Walker's family without their home.

"That was everything that we owned and we pretty much have to start all over," Walker told CNN affiliate WKBW . "We have two young kids and trying to explain to our 4-year-old that we have to move and go to a different house, it's going to be a change for her, for us."

The family says the outpouring from the community has been overwhelming. Residents have brought food, money and clothes.

"They have a lot of pieces to put back together," Walker's uncle, Robert Sands, told CNN.

"Unfortunately we couldn't take anything because there's nowhere to put it."

Walker has been a volunteer firefighter at Gratwick Hose Fire Company for two years. He helps in medical situations, Sikora said.

A sign outside the fire department now reads, "We support Ken Walker."

Brennan told CNN that he was at the fire house for 15 hours on Thursday, answering calls of support from all over the nation. One Orlando woman called and offered to fund a Disney World vacation for the Walker family, Brennan said.

Donation drive draws more than 500 donors

The community's support has been "unbelievable," Brennan said.

"The note was really enough to raise the ire of the community," he said. "I was born and raised here. This is not a racist community, nor has it ever been."

Officials hosted a donation drive in support of the Walker family Sunday, and over 500 people turned out to donate more than $15,000 and a "banquet hall full of furniture, baby clothes, diapers" and other items, Brennan said.

Many local stores and businesses have already been offering donations and support to the Walker family, according to Brennan. Additionally, donations have piled by the door of the fire company.

Two California firefighter unions and other organizations are offering Walker and his family an all-expenses-paid trip to Los Angeles that includes lodging.

Brennan said Walker and his family are very grateful.

"Ken is a very humble and very respectful and thoughtful individual," Brennan said of his colleague. The fire company president said Walker hopes to be able to return to his normal routine as quickly as possible.

Sands said his nephew's family is holding up as best as they can.

"They're doing OK. They're holding it together," he said. "They're trusting the process that law enforcement will do their job and get them some answers."