A Chicago man is behind bars after he trapped two firefighters in a basement where the floor was covered with gasoline, authorities say.

The incident occurred Tuesday after a chief and a lieutenant with the Chicago Fire Department responded to a report of a car fire on the city’s South Side, police say. After the flames were extinguished, the 47-year-old resident asked the pair to check out a potential gas leak in the basement. Once they were down there, the man threatened them with a knife and tried to lock them in, according to the Chicago P.D. The two began to struggle with the man, who had boarded up all the windows and doors in the home, says Fire Department spokesman Larry Langford. Finally, other firefighters broke through a window and got the men out of the home.

“It was very scary,’’ Langford says. “It’s speculation that this individual was trying to lure our people into a situation where they could be trapped, and he was preparing to light the accelerant with them in the basement.”