Former loanee Gavin Tomlin grabbed two goals for Paul Sturrock's men, as did
Britt Assombalonga, and although Torquay substitute Ryan Jarvis volleyed in a consolation for the Gulls, Ling knew the game was up once skipper Lee Mansell saw red.
"Once Lee Mansell went there was no hope of a fightback," he said. "We talked about a comeback at half time and went 4-4-2. Craig Easton and Damon Lathrope came off but it could have been any two from the 11 that came off because 3-0 down at half time there is only so much you can do and everyone was poor.
"It was a bad day at the office, from the first minute to the last. All I would say is that we have got an honest group of players and there are still some of the younger boys out there who are learning the trade.
"Southend are a quality team, certainly in terms of today. They showed us what it is all about and made us look very poor on the day and that is down to me as the manager, the coaching staff and the players out there. We will all be in it together."