Dearborn, MI- Authorities believe they have discovered what caused an earth-trembling explosion Monday nigh in southwest Dearbornt that entirely obliterated a garage and blew out windows around the neighborhood.

Fire officials at the scene initially thought a 100-pound liquid propane tank was the source, but further investigation suggests that it was in fact a hose connected to the tank.

Dearborn Fire Inspector Laura Ridenour said Friday the propane tank was located at the rear of the garage and was still intact after the explosion. That led investigators to the hose, which connected the propane tank to a wall-mounted heater inside the garage.

“There was either a leak where the hose connected to the heater or the hose itself may have been compromised,” she said. “Somewhere over an unknown period of time the garage filled with propane and something happened – maybe static electricity from the cold, maybe someone flipped a light switch – that caused a spark, which lit up the propane that was in there, causing the explosion.”

The hose is being sent for lab analysis, Ridenour said.

The blast, which occurred on Ross Street, west of Telegraph and one block south of Carlysle, caused extensive damage to several surrounding properties.

Houses and garages to the immediate left and right were knocked clear off their foundations and garages behind the blast site, on Carlysle, also were jolted from their foundations.

“When you go into the houses, there is carpet pulled four or five inches in the direction away from the explosion,” Ridenour said.

Blast debris, including a basketball hoop, was projected over the house that sits in front of the garage, and in some cases, went as far as across the street.

According to a police report from the incident, the family who lives at the house – a husband, wife, and child – was watching TV when the propane ignited.

The husband told police the house shook violently and all of the windows shattered inward, causing a facial laceration to his brother-in-law, who was also there.

The husband said he went into the backyard and turned off the propane tank after the explosion.

The brother-in-law required staples to close his wounds, but is expected to make a full recovery, officials said.