It was at half past six on Christmas morning that a camper exploded in central Nashville, USA.
Three people were taken to hospital and the bang caused damage to buildings and disrupted telecommunications in Tennessee and several other states.
A 63-year-old man has been identified as the suspected perpetrator.
"Just be quiet"
A neighbor of the 63-year-old tells the AP that he spoke to him a few days before the explosion.
When the neighbor asked if he expected Santa to give him something good for Christmas, the 63-year-old replied "Oh yes, Nashville and the world will never forget me", the neighbor told AP.
The neighbor says that in the study he did not think much more about what the 63-year-old said, and only afterwards understood that he must have meant the explosion.
- Nothing with this guy aroused any suspicion.
He was just quiet, the neighbor tells AP.
Unclear motive
The motive behind the explosion is still unclear.
- We hope to get an answer.
Sometimes it's impossible.
The best way to find out the subject is to talk to the person.
We will not be able to do that in this case, says David Rausch at the Tennessee police in an interview with NBC on Monday.
The 63-year-old's computer and a portable hard drive are being investigated, writes AP.
The man's bank statements from the time before the explosion are also being investigated.
The man had, among other things, made purchases of things that may have been used to build a bomb, according to the police.
During the time before the explosion in Nashville, the 63-year-old man had given away a vehicle he owned, and then said that he had been diagnosed with cancer.
However, it is unclear whether the man must have been ill.
One month before the explosion, he is also said to have given away a house he lived in for several decades, without charging for it.