SAN JOSE -- One person was killed in an early Tuesday morning fire that destroyed a small guest home located near West San Carlos Street and Meridian Avenue.

The gender of the person who died is not immediately known. The body was badly burned, and the identification will be made by the Santa Clara County Coroner's Office.

At 12:15 a.m., the San Jose Fire Department responded to the blaze on the 400 block of Willard Avenue, according to Capt. Rob Brown. Firefighters arrived at the scene at 12:21 a.m. and found a guest home behind a larger house fully involved in flames.

Firefighters were told a middle-aged man lived in the small home and was not accounted for, Brown said. "Due to the heavy fire, there was no way for us to make an attempt to get inside the structure," Brown said.

The fast-moving fire destroyed the house and caused the roof to collapse.

Eventually firefighters went inside and found a body about 6 feet away from the front door, Brown said.

The family who lives in the larger home not damaged by the fire say the man who lives in the cottage is friendly and outgoing.

"He was really nice and always said good morning," said Yesenia Castro, 21.

Castro was not home when the fire broke out, but her family members told her they heard a loud boom and then saw flames coming from the cottage.

A fire department arson investigator is working with the San Jose Police Department and Santa Clara County Coroner's Office to determine a cause for the blaze and the death of the victim.

Fire and police investigators are treating the home as a crime scene until foul play can be ruled out, Brown said.

Firefighters also battled a second Tuesday morning fire in which a resident escaped from a burning portable building after waking up to a smoke-filled room.

The man told firefighters he "was lucky to get out" of the structure located behind a commercial drywall business on the 2400 block of San Antonio Street, according to Brown.

The two-alarm blaze destroyed the portable building and threatened another structure. Firefighters responded to the blaze at 5:45 a.m. and had it knocked down in about 30 minutes.

The man was treated on scene for smoke inhalation but refused to go to the hospital. The American Red Cross Silicon Valley is helping the man with clothing and housing assistance, Brown said.

Contact Mark Gomez at 408-920-5869. Follow him on Twitter @MarkMgomez.