BRENTWOOD - Suffolk police say it was a gas leak that caused an explosion at a home on Fourth Street in Brentwood yesterday.

Investigators say they are trying to figure out if the explosion was criminal or just an accident.

A total of 10 people were forced out of their homes after the explosion. The blast was so powerful that some Long Islanders told News 12 Long Island that they felt it from miles away.

Neighbors say the house was being renovated by the new owners, Millennium Homes of Bay Shore, but Islip Town officials say they have no work permits on file for the property. The Town of Islip says it will issue violations if it finds that Millennium had been doing work without the proper permits.

The Red Cross is helping out some Long Island families that were left homeless by the blast.

Cops say 21 people were treated, but no one was seriously injured during the explosion.

Officials: Gas explosion levels Brentwood homeChopper 12 footage from the Brentwood home explosion