[SalesForce] Passing Record ID to lightning component

I am trying to implement Google Maps with lightning component and need to retrieve the record id in order to use it in the hyperlink in map marker but I am not able to access the record id in lightning controller.
Here's the part of code that's doing this job

Apex class-

public with sharing class GoogleMap {
    @AuraEnabled
    public static List<Account> getAccounts(){

        return [select id,Phone, name, BillingLatitude, BillingLongitude from Account limit 10];
    }
}

Lightning app controller js-

({
    doInit: function(component, event, helper) {
        console.log('Here 1');
        var action = component.get('c.getAccounts');

        action.setCallback(this, function(response){
            var state = response.getState();
            console.log('state:', state);
            if (state == "SUCCESS") {
                var acc = response.getReturnValue();

                if(acc.length > 0){
                   console.log('acc'+ acc[0].ID);

                    var mapOptionsCenter = {"lat":parseFloat(acc[0].BillingLatitude), "lng":parseFloat(acc[0].BillingLongitude)};
                    var mapData = Array();
                    //cmp.set("v.opportunities", response.getReturnValue());
                    for(var i=0; i<acc.length; i++){
                        mapData.push({"lat":parseFloat(acc[i].BillingLatitude), "lng":parseFloat(acc[i].BillingLongitude), "markerText":acc[i].recordid})
                    }

                    component.set('v.mapOptionsCenter', mapOptionsCenter);
                    component.set('v.mapData', mapData);
                    component.set('v.acc', acc);
                }
            }

        });
        $A.enqueueAction(action);
    }
})

So when I try to access console.log('acc'+ acc[0].ID), it says the id is undefined. Any idea how to access the id here?