Dave Grohl, a frequent guest of The Howard Stern Show, stopped by once again in September 2021 to delight the shock jock pioneer with more tales of rock n’ roll glory. Among the many yarns the Foo Fighters frontman spun for Stern was the story of his mother’s unlikely friendship with Warren Haynes.

The story began on September 11th, 2001 in the immediate aftermath of the terrorist attacks earlier that day. At the time, Grohl was on the road in Los Angeles, CA. Meanwhile, his mother, Virginia Grohl, was across the country at the family’s home in Washington, D.C., which Grohl says was only eight miles from the Pentagon, one of the sites of the attacks. Out of concern for his mother’s safety, Grohl called his management to try and put her on a tour bus to get her out of D.C. and bring her to L.A.

“About three hours later they called and said ‘okay, there’s a tour bus and they can pick her up in three hours, but there’s a catch,'” Grohl recalled. “She has to share it with Warren Haynes from Gov’t Mule and The Allman Brothers.”

Without hesitation, Grohl accepted the offer because, as anyone will tell you, “he’s the sweetest man in the world. He’s amazing.” The drummer-turned-guitarist’s mother, however, was not yet aware of this fact, so Dave had some explaining to do.

“So I called my mom and I’m like, ‘Mom, I got you a bus. Start packing. But listen, you gotta share it with this dude from The Allman Brothers,'” Grohl said.

Related: Dave & Virginia Grohl Probe Musicians’ Maternal Relationships In ‘From Cradle To Stage’ Series [Video]

And that’s how Virginia Grohl and legendary blues guitarist Warren Haynes ended up on a cross-country bus ride from Washington, D.C. to Los Angeles in the aftermath of 9/11, an experience that Dave said made them “best friends.”

Watch Dave Grohl recount the history of the unlikely bond between his mom and Warren Haynes below. You can also check out some other clips from the Nirvana drummer’s September 2021 appearance on The Howard Stern Show.

Dave Grohl’s Mom Got a Ride With Warren Haynes on 9/11

Dave Grohl on the One Night He Got to Play With Iggy Pop

Dave Grohl on Leaving Scream, Joining Nirvana, and What He Bought With His 1st Check

How Dave Grohl Getting Dumped in 7th Grade Led to Him Becoming a Rock Star

Dave Grohl Demonstrates How He Drums With His Teeth

Dave Grohl’s Dad Thought His Music Career Wouldn’t Last More Than a Year