Scared Single Mom Cheryl Cole Builds Panic Room After Split From Liam Payne

Cheryl Cole is turning her English retreat into a fortress after splitting with her One Direction boyfriend, Liam Payne.

The mom-of-one insisted the state-of-the-art safety measure — worth tens of thousands of dollars — be installed at her home after her former X Factorboss, Simon Cowell, recommended she invest in the precaution.

A source told RadarOnline.com that Cowell gave Cole, 35, the advice after killer burglar Darren February stole expensive jewelry from the music mogul, as he, his partner Lauren Silverman and their then-22-month-old son, Eric, slept.

"Cheryl has always been huge on having massive security measures at her homes, and now she has a new family to take care of so she is stepping things up a notch," an insider told RadarOnline.com, noting the extreme security measure will not be a concrete bunker, but will feature access to a toilet, CCTV, beds and an emergency phone line.

"After what happened to Simon with his burglary," added the insider, "he began to advise all his close celebrity pals to increase their security measures as he knows how important it is to invest in protecting his loved ones."

Cole, whose son Bear turned 1 in March, has good reason to be nervous about her safety, because she's suffered a string of disturbing security issues through the years.

In 2006, Cole revealed the "terrible time" she suffered at the hands of telephone harassers who bombarded her with filthy calls.

While in the group Girls Aloud she was also plagued with stalkers, including a crazed lesbian.

And in 2010, X Factor UK host Dermot O'Leary raised the alarm after picking up a rape threat against Cole on his voicemail.