Metro’s Anna Chen is happy she can now be reached by HQ even when riding underground.

Some of you have already noticed this: underground cell phone service for T-Mobile customers is now up and running on the Metro Red and Purple Lines between Union Station and Wilshire/Western in  Los Angeles.

Service for Verizon and Sprint customers began earlier this year between Union Station and 7th/Metro, including the platforms at 7th/Metro for the Blue and Expo Lines. Negotiations are underway between InSite Wireless Group — the firm under contract with Metro to provide the needed equipment for the service — and AT&T to provide underground cell service.

In the event of an emergency, riders are reminded to first contact the train operator via the emergency intercom system located on board trains and on station platforms before calling 9-1-1. Riders also can use the text feature on the Transit Watch app on their smartphones to report issues directly to the Los Angeles County Sheriff’s Department.

Verizon and Sprint cell phone service is accessible from Union Station to 7th Street Metro Center Station, with work underway to expand to the Wilshire/Western station later this year.

Subsequent phases of the program will expand the service on the Red Line from Wilshire/Vermont Station to the North Hollywood Station in the San Fernando Valley. Service will also be provided on Metro Gold Line underground stations in Pasadena and in East Los Angeles. Those expansions should be completed in 2017.