An exploding propane tank on a lunch truck sent a ball of fire across a Philadelphia street on Tuesday, critically injuring two people and spreading debris far and wide, police said.
"The fireball engulfed the entire truck and crossed the street," said Philadelphia Chief Inspector Scott Small.
Eleven people in total were sent to area hospitals with injuries from the blast in the tightly-packed Feltonville neighborhood of Philadelphia, but five of them were treated and released, said Small said.
A 14-year-old girl and a 21-year-old woman with burns over more than 50 percent of their bodies were hospitalized in critical condition, he said. The other four people who were injured are in stable condition, he said.
The truck, bearing the name of La Parrillada Chapina, was reportedly parked by an auto body shop on 3rd Street and Wyoming Avenue at the time of the explosion.
The explosion sent the propane tank flying from the food truck about 150 feet (46 meters) into the backyard of a nearby rowhome, Small said.
A car that was passing by at the time of the explosion remained at the scene on Tuesday evening - its scorched gold paint showing the effects of the blast.
Pieces of debris, including the door from the hatch where the propane tank was stored, littered the street.
The cause of the explosion is still under investigation, and Small said investigators are trying to determine whether the blast was accidental or the result of foul play.