npm install -g react-native-cli errors

I typed the command to install react-native-cli using "> npm install -g react-native-cli", and got the following error messages. Advise?

module.js:538
throw err;
^

Error: Cannot find module '../lib/utils/unsupported.js'
at Function.Module._resolveFilename (module.js:536:15)
at Function.Module._load (module.js:466:25)
at Module.require (module.js:579:17)
at require (internal/module.js:11:18)
at /usr/local/lib/node_modules/npm/bin/npm-cli.js:19:21
at Object. (/usr/local/lib/node_modules/npm/bin/npm-cli.js:92:3)
at Module._compile (module.js:635:30)
at Object.Module._extensions..js (module.js:646:10)
at Module.load (module.js:554:32)
at tryModuleLoad (module.js:497:12)
Julies-Mac-mini:~ juliechen$ pwd
/Users/juliechen
Julies-Mac-mini:~ juliechen$ sudo npm install -g react-native-cli
Password:
module.js:538
throw err;
^

Error: Cannot find module '../lib/utils/unsupported.js'
at Function.Module._resolveFilename (module.js:536:15)
at Function.Module._load (module.js:466:25)
at Module.require (module.js:579:17)
at require (internal/module.js:11:18)
at /usr/local/lib/node_modules/npm/bin/npm-cli.js:19:21
at Object. (/usr/local/lib/node_modules/npm/bin/npm-cli.js:92:3)
at Module._compile (module.js:635:30)
at Object.Module._extensions..js (module.js:646:10)
at Module.load (module.js:554:32)
at tryModuleLoad (module.js:497:12)