One man remains in critical condition after an intense fire at a Brooklyn apartment building that firefighters say was sparked by a charging lithium-ion battery. The fire broke out inside the building just before 6:40 a.m. Thursday on Avenue M in the Midwood section. At least four people were hurt in the fire. A man was rushed to the hospital with life-threatening injuries. The 30-year-old man is being treated for severe burns at Staten Island University Hospital North. The other people being treated for injuries are all expected to survive. Dramatic video showed firefighters entering the lobby and pulling out what appeared to be an e-bike that was engulfed in flames and blocking the stairwell. It is believed to be the property of one of the injured victims. Multiple e-bike batteries were also apparently found on fire inside.