Cabazon, Calif. ? Authorities investigating an arson wildfire that killed four firefighters questioned two people Monday, while firefighters finally contained the blaze after five days.

Sheriff’s deputies took two men and three bags of material from a house in Cabazon, said neighbor Robert Dunham, 70, who lives three doors down from the residence a quarter-mile from where the fire started.

Authorities released little information about the two people who were interviewed at a sheriff’s station and later released. No arrests had been made.

“We’re trying to work through the leads that we have, and going through the process,” Riverside County Sheriff Bob Doyle said in a telephone interview.

Authorities said the fire was deliberately set at the base of a slope in Cabazon, west of Palm Springs. Cabazon residents have said they saw two young men leaving the area where the fire began.

The fire started around 1 a.m. Thursday and burned 63 square miles, or 40,200 acres, until it was fully contained Monday night. It has destroyed 54 structures – 34 homes and 20 other buildings.

Last week, a shift in the winds turned deadly when a gust pushed a wall of flames around five firefighters trying to protect a house. Four firefighters died, while another was hospitalized with serious burns over most of his body.

Pablo Cerda, 23, remained in critical condition Monday, three days after undergoing surgery to remove damaged skin.

About 50 of Cerda’s relatives gathered at the hospital, praying for him. “They want everyone to know that Pablo’s dream was to help people, and on Thursday morning, that’s just what he was doing – protecting and serving,” said Eddie Cortez, a family spokesman.

Meanwhile, the FBI and the Bureau of Alcohol, Tobacco, Firearms and Explosives donated $25,000 each to the reward pool, bringing the total to $550,000, ATF spokeswoman Susan Raichel said.

Vigils were held at several Southern California churches and fire stations for Cerda and to pray for the families of the fallen firefighters. Killed were Mark Loutzenhiser, 43, of Idyllwild; Jason McKay, 27, of Phelan; Jess McLean, 27, of Beaumont; and Daniel Hoover-Najera, 20, of San Jacinto.