T-Mobile suffered a national outage of its high-speed LTE data wireless service on Wednesday night and into Thursday morning.

After widespread complaints about the outage on Twitter twtr and other social media, the third-largest wireless carrier acknowledged the problem at 3:30 a.m ET. “We’re aware of reported instances of LTE outages,” T-Mobile wrote from its official account. “So sorry for any inconvenience. Our engineers are on it right now working hard to resolve.”

A few hours later, T-mobile said the problem had been resolved. “Annnnnd we’re back! Appreciate everyone’s patience,” the company tweeted.

The problem knocking out high speed data connections occurred due to routine maintenance, a spokeswoman said. “If customers are still experiencing issues, we’re recommending they try powering down and back up, but the network is fully back.”

The outage comes at a tricky time as T-Mobile tmus is battling for customers in the increasingly competitive mobile market. Verizon vz has touted the quality of its network as a major reason why customers should stick with its service, while Sprint s has also been playing up improvements in network quality in recent ads.

 

 

And some competitors jumped on social media to make sure no one missed the connection. “‘RELIABLE’ isn’t an advertising buzzword, it is tangible,” Verizon spokesman Jeff Nelson tweeted. “Last night, customers of a Verizon competitor learned that the hard way.”

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All of the carriers have suffered from occasional outages over the years, including Verizon, of course.

T-Mobile has not announced any kind of promotion or compensation for customers hit by the outage, which didn’t effect voice calls. Cricket Wireless, the prepaid service owned by AT&T t , suffered a short outage in June and offered customers a $5 credit to make up for the lost service.