Wednesday, a pilot heard a whistling noise coming from a cockpit window. Passengers left the plane so crews can test the cabin pressure. It was a false alarm.

Now, we've learned that Thursday, a baggage handler cart hit the curb, shearing off a wheel and tipping the cart. Another Alaska Employee says he saw what happened. He called us, but didn't want his name used.

He says the problems are worse than anyone knows and blames Alaska's new baggage company.

"Since they started working there I've never seen more carts flipped over and wrecked and beat out," the worker said. "I've worked with these people on a continual basis and it's almost like they don't care."

"There is increased scrutiny across the board about safety in the bag well area and on the tarmac with our aircraft," said Caroline Boren, Alaska Airlines Spokeswoman. She adds, "We also have an executive team that's looking across the board at the incidents that happened this week to see if there's any other steps we can take to prevent this from happening again."

Sea-Tac Airport is also watching closely. In May, Alaska fired its union ground crews. The British company Menzies took over. A spokesman for Menzies in Britain, reached by phone, had no comment on the recent incidents.

Since the company took over, Sea-Tac says it has seen an increase in ground incidents.

"I think we see the same things everyone else is seeing and we're concerned and we very much want to make sure we get clarity with the airline, with the vendor Menzies, and make sure we all are on the same page because ultimately that's where we need to be," said Sea-Tac Spokesman Bob Parker.

But Alaska tells KOMO 4 News it is committed to working with Menzies.

"We really have seen a strong track record and then with the incidents this week we've also seen them be very responsive to our concerns and taking the steps that are needed to prevent this in the future. So at this point that's the focus," said Caroline Boren.