Police Powers please see detail below for the details?

My Car had a damaged fender. I came home late night and stumbled into my apt. someone called the cops and said they saw someone drive through the parking lot with damage and the lone male driver exited and stumble into building c. The police came and ran my plates theytried calling me and knocking on the door. I was asleep. The entred my unit and arrested me for dui. They said they had resonable concern for my safety. SInce my apt was dark, and they could here no activity from within. and since i may be intoxicated and had been in an accident. they claim that was cause for lawful entry since my safety was a concern. But no one reported an accident. and no one indentified me or anyone go into my unit. just my bulding. Is that legal entry?