npm install bootstrap@4.0.0-alpha.2 --save

npm install @ng-bootstrap/ng-bootstrap --save

// map tells the System loader where to look for things
var map = {
 'app':      'dist', // 'dist',
 '@angular':     'node_modules/@angular',
 'angular2-in-memory-web-api': 'node_modules/angular2-in-memory-web-api',
 'rxjs':      'node_modules/rxjs',
 // add ng-bootstrap location map 
 '@ng-bootstrap':    'node_modules/@ng-bootstrap'
};
// packages tells the System loader how to load when no filename and/or no extension
var packages = {
 'app': { main: 'main.js', defaultExtension: 'js', format: 'amd' },
 'rxjs': { defaultExtension: 'js' },
 'angular2-in-memory-web-api': { main: 'index.js', defaultExtension: 'js' },
 // add ng-bootstrap package config
 '@ng-bootstrap/ng-bootstrap': { main: 'index.js', defaultExtension: 'js' }
};

<link rel="stylesheet" href="node_modules/bootstrap/dist/css/bootstrap.css"/>

import { Component, OnInit } from '@angular/core';
import { HTTP_PROVIDERS } from '@angular/http';
import { provideRouter, ROUTER_DIRECTIVES } from '@angular/router';
// import ng-bootstrap directives
import { NGB_DIRECTIVES, NGB_PRECOMPILE } from '@ng-bootstrap/ng-bootstrap';

import { routes } from './app.routes';

@Component({
 //moduleId: module.id,
 selector: 'app',
 providers: [ HTTP_PROVIDERS ],
 templateUrl: 'dist/app.component.html',
 styleUrls: ['dist/app.component.css'],
 // ng-bootstrap required precompile directives
 precompile: [NGB_PRECOMPILE],
 // add ng-bootstrap directives to app
 directives: [
  ROUTER_DIRECTIVES, NGB_DIRECTIVES
 ],
 pipes: []
})
export class AppComponent implements OnInit {

 ngOnInit() {
 }

}

<p>
 <ngb-alert [dismissible]="false">
 <strong>Warning!</strong> Better check yourself, you're not looking too good.
 </ngb-alert>
</p>

export class AppComponent implements OnInit {

 alert: IAlert[];

 ngOnInit() {
  this.alert = [
   {
    id: 1,
    type: 'success',
    message: 'This is an success alert',
   },
   {
    id: 2,
    type: 'info',
    message: 'This is an info alert',
   },
   {
    id: 3,
    type: 'warning',
    message: 'This is a warning alert',
   },
   {
    id: 4,
    type: 'danger',
    message: 'This is a danger alert',
   }
  ];
 }

 closeAlert(alert: IAlert) {
  const index: number = this.alerts.indexOf(alert);
  this.alerts.splice(index, 1);
 }
}

interface IAlert {
 id: number;
 type: string;
 message: string;
}

<p *ngFor="let alert of alerts">
 <ngb-alert
  [type]="alert.type"
  (close)="closeAlert(alert)">\{\{ alert.message }}
 </ngb-alert>
</p>