The phrase "to look into" means to investigate, examine or inquire about something. It can be used as a verb and is often used when referring to an official investigation or inquiry conducted by someone in authority such as a government agency, law enforcement officer or a judge. For example, if there was an accident at work, the authorities might "look into" the cause of the incident to determine what went wrong and how it could be prevented from happening again. The phrase can also be used more generally to mean simply taking a closer look or trying to find out more information about something.