npm startができない！

Angular2のチュートリアル中、突然npm startができなくなってしまいました。
コードが間違っているかと思ってexampleのコードと見比べるも異なる部分は見つからず、ならばと思いnpm startができた頃の状態にgit reset --hard HEADしてみましたが、それでも上手くいきません。エラーは

$ npm start

> angular-quickstart@1.0.0 prestart /home/vagrant/angular2-tutorial
> npm run build


> angular-quickstart@1.0.0 build /home/vagrant/angular2-tutorial
> tsc -p src/

src/app/hero-detail.component.ts(24,117): error TS2339: Property ‘hero’ does not exist on type ‘HeroDetailComponent’.

npm ERR! Linux 2.6.32-642.4.2.el6.x86_64
npm ERR! argv “/home/vagrant/.nvm/versions/node/v6.10.3/bin/node” “/home/vagrant/.nvm/versions/node/v6.10.3/bin/npm” “run” “build”
npm ERR! node v6.10.3
npm ERR! npm  v3.10.10
npm ERR! code ELIFECYCLE
npm ERR! angular-quickstart@1.0.0 build: `tsc -p src/`
npm ERR! Exit status 2
npm ERR! 
npm ERR! Failed at the angular-quickstart@1.0.0 build script ‘tsc -p src/‘.
npm ERR! Make sure you have the latest version of node.js and npm installed.
npm ERR! If you do, this is most likely a problem with the angular-quickstart package,
npm ERR! not with npm itself.
npm ERR! Tell the author that this fails on your system:
npm ERR!     tsc -p src/
npm ERR! You can get information on how to open an issue for this project with:
npm ERR!     npm bugs angular-quickstart
npm ERR! Or if that isn’t available, you can get their info via:
npm ERR!     npm owner ls angular-quickstart
npm ERR! There is likely additional logging output above.

npm ERR! Please include the following file with any support request:
npm ERR!     /home/vagrant/angular2-tutorial/npm-debug.log

npm ERR! Linux 2.6.32-642.4.2.el6.x86_64
npm ERR! argv “/home/vagrant/.nvm/versions/node/v6.10.3/bin/node” “/home/vagrant/.nvm/versions/node/v6.10.3/bin/npm” “start”
npm ERR! node v6.10.3
npm ERR! npm  v3.10.10
npm ERR! code ELIFECYCLE
npm ERR! angular-quickstart@1.0.0 prestart: `npm run build`
npm ERR! Exit status 1
npm ERR! 
npm ERR! Failed at the angular-quickstart@1.0.0 prestart script ‘npm run build’.
npm ERR! Make sure you have the latest version of node.js and npm installed.
npm ERR! If you do, this is most likely a problem with the angular-quickstart package,
npm ERR! not with npm itself.
npm ERR! Tell the author that this fails on your system:
npm ERR!     npm run build
npm ERR! You can get information on how to open an issue for this project with:
npm ERR!     npm bugs angular-quickstart
npm ERR! Or if that isn’t available, you can get their info via:
npm ERR!     npm owner ls angular-quickstart
npm ERR! There is likely additional logging output above.

npm ERR! Please include the following file with any support request:

npm ERR!     /home/vagrant/angular2-tutorial/npm-debug.log